Piperidine derivatives for use in the treatment of pancreatic cancer

ABSTRACT

The present invention relates to novel piperidine derivatives having better cell growth inhibitory activities toward cancer cell cultures and, more particularly, PANC-1 cancer cell cultures than FK866. Accordingly, the present invention relates to compounds of formula I, wherein Ar 1  is aryl or heteroaryl, which are optionally substituted by one, two or three substituents selected from lower alkyl; lower alkoxy; formyl; hydroxyl; lower alkyl substituted by lower alkoxy or hydroxyl; A is C n H 2n , C n H 2n−2  or C n H 2n−4 , wherein n=4, 5, 6, 7; B is ═N—CN, oxo (═O), thio (═S); D is NH, —CH═CH—; Ar 2  is aryl or heteroaryl which are optionally substituted by one, two or three halogen substituents; wherein, if B is oxo (═O), Ar 1  and Ar 2  are not simultaneously phenyl and pyridine-3-yl; B and D are not simultaneously ═N—CN and —CH═CH—, or a pharmaceutically acceptable salt, a racemic mixture or its corresponding enantiomers and/or optical isomers. The compounds of formula I and their pharmaceutically usable addition salts possess valuable pharmacological properties. Specifically, it has been found that the compounds of the present invention, alone or in combination with other therapeutic active compounds, have an activity as chemotherapeutic agents against cancer and, more particularly, pancreatic cancers.

The present invention relates to piperidine derivatives and their use aschemotherapeutic agents against cancers and, more particularly,pancreatic cancers.

Alterations in cell metabolism have emerged as one of the hallmarks ofcancer that could possibly lead to new targeted therapeutic approaches(Hanahan D, Weinberg R A. Hallmarks of cancer: the next generation.Cell. 2011; 144(5):646-74). Among the features distinguishing cancercells from their normal counterparts there is an upregulatednicotinamide adenine dinucleotide (NAD) biosynthesis, which is needed toface increased proliferation, metabolic processes, as well as NADconsumption by cell signaling proteins and DNA repair enzymes. Thus,depleting NAD synthesis has been proposed as a novel strategy inoncology and the NAD biosynthetic machinery is emerging as a highlypromising therapeutic target (Montecucco F, Cea M, Bauer I, Soncini D,Caffa I, Lasiglie D, et al. Nicotinamide phosphoribosyltransferase(NAMPT) inhibitors as therapeutics: rationales, controversies, clinicalexperience. Current drug targets. 2013; 14(6):637-43). NAD could besynthesized from various precursors that include tryptophan, nicotinicacid (NA), nicotinamide riboside (NR), and nicotinamide (NAM), thelatter being widely used in mammalian cells. The enzyme nicotinamidephosphoribosyltransferase (NAMPT) enzyme catalyzes the first reaction ofthe synthesis of NAD from nicotinamide. NAMPT is a promising therapeutictarget for cancers. Mounting evidence indicates that NAMPT is frequentlyup-regulated in many cancers (Shackelford R E, Mayhall K, Maxwell N M,Kandil E, Coppola D. Nicotinamide phosphoribosyltransferase inmalignancy: a review. Genes & cancer. 2013; 4(11-12):447-56.).

Previous clinical studies have demonstrated that most cancer cells aresensitive to(E)-N-[4-(1-benzoylpiperidin-4-yl)butyl]-3-(pyridin-3-yl)acrylamide,also kwon as FK866, a NAMPT inhibitor-mediated cell death, withoutsignificant toxicity to animals (Nahimana A, Attinger A, Aubry D,Greaney P, Ireson C, Thougaard A V, Tjornelund J, Dawson K M, Dupuis M,Duchosal M A. The NAD biosynthesis inhibitor FK866 has potent antitumoractivity against hematologic malignancies. Blood. 2009 Apr. 2;113(14):3276-86.). However, the specific cell growth inhibitory activitytoward PANC-1 cancer cell cultures of FK866 is relatively low.Furthermore, compound FK866 failed in clinical phase II most probablydue to its too short lifetime in vivo and its low water solubility(Goldinger S M, Gobbi Bischof S, Fink-Puches R, Klemke C D, Dréno B,Bagot M, Dummer R. Efficacy and Safety of AP0866 in Patients WithRefractory or Relapsed Cutaneous T-Cell Lymphoma: A Phase 2 ClinicalTrial. JAMA Dermatol. 2016 Mar. 23. doi:10.1001/jamadermatol.2016.0401.).

The present invention relates to novel piperidine derivatives havingbetter cell growth inhibitory activities toward cancer cell cultures,particularly toward PANC-1 cancer cell cultures, than FK866.Accordingly, the present invention relates to compounds of formula I

wherein

-   Ar₁ is aryl or heteroaryl, which are optionally substituted by one,    two or three substituents selected from lower alkyl; lower alkoxy;    formyl; hydroxyl; lower alkyl substituted by lower alkoxy or    hydroxyl;-   A is C_(n)H_(2n), C_(n)H_(2n−2), C_(n)H_(2n−4), wherein n=4, 5, 6,    7;-   B is ═N—CN, oxo (═O), thio (═S);-   D is NH, —CH═CH—;-   Ar₂ is aryl or heteroaryl which are optionally substituted by one,    two or three halogen substituents

wherein,

if B is oxo (═O), Ar₁ and Ar₂ are not simultaneously phenyl andpyridine-3-yl;

B and D are not simultaneously ═N—CN and —CH═CH—.

or a pharmaceutically acceptable salt, a racemic mixture or itscorresponding enantiomers and/or optical isomers.

The following definitions of the general terms used in the presentdescription apply irrespective of whether the terms in question appearalone or in combination.

As used herein, the term “aryl” denotes a carbocyclic ring system,containing from 6 to 10 carbon atoms forming one or more rings, andwherein at least one ring is aromatic in nature, for example phenyl ornaphthyl.

The term “heteroaryl” denotes a carbocyclic ring system, containing from5 to 10 ring atoms forming one or more rings, wherein at least onecarbon atom is replaced by a heteroatom, selected from the groupconsisting of O, N or S, and wherein at least one ring is aromatic innature, for example oxazolyl, pyridyl, thiophenyl, quinolinyl, pyrrolyl,furyl, benzoimidazolyl, imidazolyl and the like.

The term “lower alkyl” denotes a saturated, aliphatic hydrocarbon groupincluding a straight or branched carbon chain with 1-4 carbon atoms.Examples for “alkyl” are methyl, ethyl, n-propyl and isopropyl.

The term “lower alkoxy” denotes a group —O—R′ wherein R′ is lower alkylas defined above.

The term “lower alkyl substituted by hydroxy” denotes a lower alkylgroup, wherein at least one hydrogen atom, preferably one, two or threehydrogen atoms, is replaced by a hydroxy group.

The term “lower alkyl substituted by lower alkoxy” denotes a lower alkylgroup, wherein at least one hydrogen atom, preferably one, two or threehydrogen atoms, is replaced by a lower alkoxy group as defined above.

The term “halogen” denotes chlorine, bromine, fluorine or iodine.Preferred halogen is fluorine.

The term “pharmaceutically acceptable salt” or “pharmaceuticallyacceptable acid addition salt” embraces salts with inorganic and organicacids, such as hydrochloric acid, nitric acid, sulfuric acid, phosphoricacid, citric acid, formic acid, fumaric acid, maleic acid, acetic acid,nrpopionic acid, hexanoic acid, octanoic acid, lauric acid, benzoicacid, cinnamic acid, succinic acid, tartaric acid, malic acid, lacticacid, camphanic acid, methanesulfonic acid, p-toluenesulfonic acid,camphorsulfonic acid and the like.

Preferably, Ar₁ is phenyl; thiophen; furan; oxazole; pyrrol; which areoptionally substituted by one, two or three substituents selected fromlower alkyl; lower alkoxy; formyl; hydroxyl; lower alkyl substituted byone, two or three lower alkoxy or hydroxyl. Preferred compounds arethose wherein Ar₁ is phenyl; thiophen-2-yl; 2,4-dimethoxyphenyl;2,6-dimethoxyphenyl; 2,4,6-trimethoxyphenyl; 3-methoxyfuran-2-yl;furan-2-yl; 1,2-oxazole-5-yl; 4-formyl-2,6-dimethoxyphenyl;4-(dimethoxymethyl)-2,6-dimethoxyphenyl; 5-hydroxy-2-methylfuro-2-yl;5-formyl-2-methylfuro-3-yl; 4-hydroxymethyl-2,6-dimethoxyphenyl;4-formyl-2,6-dimethoxyphenyl; 4-formyl-2-methyl-1-propyl-pyrrol-3-yl.Still more preferred are those compounds wherein Ar₁ is2,4-dimethoxyphenyl; 2,6-dimethoxyphenyl; 2,4,6-trimethoxyphenyl.

According to another preferred embodiment of the present invention, Ar₂is pyridine; pyridazin; diazin; which are optionally substituted by one,two or three halogen substituents. The halogen substituent is (are)preferably fluorine. Preferred embodiments are those wherein Ar₂ ispyridin-3-yl; 2-fluoropiyridin-3-yl; 4-fluoropyridin-3-yl;5-fluoropyridin-3-yl; 2,4-difluoropyridin-3-yl;2,6-difluoropyridin-3-yl; pyridin-4-yl; 2-fluoropyridin-4-yl;3-fluoropyridin-4-yl; 6-fluoropyridin-4-yl; 2,3-difluoropyridin-4-yl;2,5-difluoropyridin-4-yl; 3,5-difluropyridin-4-yl;2,4,5-trifluoropyridin-4-yl; pyridazin-5-yl; 1,2-diazin-4-yl; Still morereferred compounds are those wherein Ar₂ is 2-fluoropyridin-4-yl;3-fluoropyridin-4-yl; 6-fluoropyridin-4-yl; 2,3-difluoropyridin-4-yl;2,5-difluoropyridin-4-yl; 3,5-difluropyridin-4-yl;2,4,5-trifluoropyridin-4-yl.

According to another preferred embodiment of the present invention, B is═N—CN

According to another preferred embodiment of the present invention, A isC_(n)H_(2n), C_(n)H_(2n−2) or C_(n)H_(2n) and n is 4 or 5. Preferably Ais C₄H₈ and, still more preferably, C₅H₁₀.

Still according to another preferred embodiment of the presentinvention, D is NH

Still according to another preferred embodiment of the presentinvention, Ar₂ is 2-fluoropyridin-4-yl; 3-fluoropyridin-4-yl;6-fluoropyridin-4-yl; 2,3-difluoropyridin-4-yl;2,5-difluoropyridin-4-yl; 3,5-difluropyridin-4-yl;2,4,5-trifluoropyridin-4-yl.

Still more preferably, the present invention relates to compounds ofFormula I wherein

A is C₄H₈, C₅H₁₀

B is ═N—CN;

D is NH

Ar₁ is 2,4-dimethoxyphenyl; 2,6-dimethoxyphenyl; 2,4,6-trimethoxyphenyl;

Ar₂ is 2-fluoropyridin-4-yl; 3-fluoropyridin-4-yl; 6-fluoropyridin-4-yl;2,3-difluoropyridin-4-yl; 2,5-difluoropyridin-4-yl;3,5-difluropyridin-4-yl; 2,4,5-trifluoropyridin-4-yl.

Preferred compounds according to the present invention are

-   (E)-3-(2-fluoropyridin-3-yl)-N-4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)acrylamide-   (E)-N-(4-1-(2,6-dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(2-fluoropyridin-3-yl)acrylamide-   (E)-N-(4-(1-benzoylpiperidin-4-yl)butyl)-3-(2-fluoropyridin-3-yl)acrylamide-   (E)-3-(2,6-difluoropyridin-3-yl)-N-(4-1-(2,6-dimethoxybenzoyl)piperidin-4-yl)butyl)    acrylamide-   (E)-3-(2-fluoropyridin-3-yl)-N-(4-1-(5-(hydroxymethyl-2-methylfuro-3-yl)piperidin-4-yl)butyl)    acrylamide-   (E)-3-(2-fluoropyridin-3-yl)-N-(4-(1-(5-formyl-2-methylfuro-3-yl)piperidin-4-yl)butyl)    acrylamide-   (E)-3-(2-fluoropyridin-3-yl)-N-(4-(1-(4-(hydroxymethyl)-2,6-dimethoxybenzoyl))piperidin-4-yl)butyl)acrylamide-   (E)-3-(2-fluoropyridin-3-yl)-N-(4-(1-(4-formyl-2,6-dimethoxybenzoyl))piperidin-4-yl)butyl)    acrylamide-   (E)-3-(2-fluoropyridin-3-yl)-N-(4-(1-(4-formyl-2-methyl-1-propyl-1H-pyrrole-3-carbonyl)piperidin-4-yl)butyl)acrylamide-   (E)-N-(4-(1-benzoylpiperidin-4-yl)butyl)-3-(2,6-difluoropyridin-4-yl)acrylamide-   (E)-3-(2,6-difluoropyridin-3-yl)-N-4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)    acrylamide-   (E)-3-(2,6-difluoropyridin-3-yl)-N-4-(1-(furan-2-carbonyl)piperidin-4-yl)butyl)acrylamide-   (E)-N-(4-(1-(2,4-Dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide-   (E)-N-(4-(1-(2,6-Dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide-   (E)-3-(Pyridin-3-yl)-N-(4-(1-(2,4,6-trimethoxybenzoyl)piperidin-4-yl)butyl)acrylamide-   (E)-N-(4-(1-(3-Methoxyfuran-2-carbonyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide-   (E)-N-(4-(1-(Isoxazole-5-carbonyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide-   (E)-N-(4-(1-(4-Formyl-2,6-dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide-   (E)-N-((E)-4-(1-Benzoylpiperidin-4-yl)but-2-en-1-yl)-3-(pyridin-3-yl)acrylamide-   (E)-N-((E)-4-(1-(2,6-Dimethoxybenzoyl)piperidin-4-yl)but-2-en-1-yl)-3-(pyridin-3-yl)acrylamide-   (E)-3-(Pyridin-3-yl)-N-((E)-4-(1-(2,4,6-trimethoxybenzoyl)piperidin-4-yl)but-2-en-1-yl)acrylamide-   (E)-N-((E)-4-(1-(Furan-2-carbonyl)piperidin-4-yl)but-2-en-1-yl)-3-(pyridin-3-yl)acrylamide-   (E)-3-(Pyridin-3-yl)-N-((E)-4-(1-(thiophene-2-carbonyl)piperidin-4-yl)but-2-en-1-yl)acrylamide-   (E)-N-(4-(1-Benzoylpiperidin-4-yl)butyl)-3-(pyridazin-4-yl)acrylamide-   (E)-N-(4-(1-(Furan-2-carbonyl)piperidin-4-yl)butyl)-3-(pyridazin-4-yl)acrylamide-   (E)-3-(Pyridazin-4-yl)-N-(4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)acrylamide-   (E)-N-(4-(1-(2,6-Dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridazin-4-yl)acrylamide-   1-(4-(1-Benzoylpiperidin-4-yl)butyl)-3-(pyridin-3-yl)urea-   1-(4-(1-(Furan-2-carbonyl)piperidin-4-yl)butyl)-3-(pyridin-3-Aurea-   1-(Pyridin-3-yl)-3-(4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)urea-   1-(4-(1-(2,6-Dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridin-3-Aurea-   1-(4-(1-Benzoylpiperidin-4-yl)butyl)-3-(pyridin-4-yl)urea-   1-(4-(1-(Furan-2-carbonyl)piperidin-4-yl)butyl)-3-(pyridin-4-Aurea-   1-(Pyridin-4-yl)-3-(4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)urea-   1-(4-(1-(2,6-Dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridin-4-Aurea-   (E)-1-(4-(1-Benzoylpiperidin-4-yl)butyl)-2-cyano-3-(pyridin-4-yl)guanidine-   (E)-2-Cyano-1-(4-(1-(2,6-dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridin-4-yl)guanidine-   (E)-2-Cyano-1-(4-(1-(furan-2-carbonyl)piperidin-4-yl)butyl)-3-(pyridin-4-yl)guanidine-   (E)-2-Cyano-1-(pyridin-4-yl)-3-(4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)guanidine-   (E)-2-cyano-1-(4-(1-(4-(dimethoxymethyl)-2,6-dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridazin-4-yl)guanidine-   (E)-2-Cyano-1-(4-(1-(furan-2-carbonyl)piperidin-4-yl)butyl)-3-(pyridazin-4-yl)guanidine-   (E)-1-(4-(1-Benzoylpiperidin-4-yl)butyl)-2-cyano-3-(6-fluoropyridin-3-yl)guanidine-   (E)-2-Cyano-1-(4-(1-(2,6-dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(6-fluoropyridin-3-yl)guanidine-   (E)-2-cyano-1-(4-(1-(4-(dimethoxymethyl)-2,6-dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(6-fluoropyridin-3-yl)guanidine-   (E)-2-Cyano-1-(6-fluoropyridin-3-yl)-3-(4-(1-(furan-2-carbonyl)piperidin-4-yl)butyl)guanidine-   (E)-2-Cyano-1-(6-fluoropyridin-3-yl)-3-(4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)guanidine-   (E)-1-(5-(1-Benzoylpiperidin-4-yl)pentyl)-2-cyano-3-(pyridin-3-yl)guanidine-   (E)-2-Cyano-1-(5-(1-(furan-2-carbonyl)piperidin-4-yl)pentyl)-3-(pyridin-3-yl)guanidine-   (E)-2-Cyano-1-(pyridin-3-yl)-3-(5-(1-(thiophene-2-carbonyl)piperidin-4-yl)pentyl)guanidine-   (E)-1-(5-(1-Benzoylpiperidin-4-yl)pentyl)-2-cyano-3-(pyridin-4-yl)guanidine-   (E)-2-Cyano-1-(5-(1-(furan-2-carbonyl)piperidin-4-yl)pentyl)-3-(pyridin-4-yl)guanidine-   (E)-2-Cyano-1-(pyridin-4-yl)-3-(5-(1-(thiophene-2-carbonyl)piperidin-4-yl)pentyl)guanidine-   (E)-2-Cyano-1-(5-(1-(2,6-dimethoxybenzoyl)piperidin-4-yl)pentyl)-3-(pyridin-4-yl)guanidine-   (E)-1-((E)-5-(1-Benzoylpiperidin-4-yl)pent-2-en-1-yl)-2-cyano-3-(pyridin-3-yl)guanidine-   (E)-2-Cyano-1-((E)-5-(1-(furan-2-carbonyl)piperidin-4-yl)pent-2-en-1-yl)-3-(pyridin-3-yl)guanidine-   (E)-2-Cyano-1-(pyridin-3-yl)-3-((E)-5-(1-(thiophene-2-carbonyl)piperidin-4-yl)pent-2-en-1-yl)guanidine-   (E)-2-Cyano-1-((E)-5-(1-(2,6-dimethoxybenzoyl)piperidin-4-yl)pent-2-en-1-yl)-3-(pyridin-3-yl)guanidin-   (E)-1-((E)-5-(1-Benzoylpiperidin-4-yl)pent-2-en-1-yl)-2-cyano-3-(pyridin-4-yl)guanidine-   (E)-2-Cyano-1-((E)-5-(1-(furan-2-carbonyl)piperidin-4-yl)pent-2-en-1-yl)-3-(pyridin-4-yl)guanidine-   (E)-2-Cyano-1-(pyridin-4-yl)-3-((E)-5-(1-(thiophene-2-carbonyl)piperidin-4-yl)pent-2-en-1-yl)guanidine-   (E)-2-Cyano-1-((E)-5-(1-(2,6-dimethoxybenzoyl)piperidin-4-yl)pent-2-en-1-yl)-3-(pyridin-4-yl)guanidine-   1-(4-(1-Benzoylpiperidin-4-yl)butyl)-3-(pyridin-3-yl)thiourea-   1-(4-(1-(Furan-2-carbonyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)thiourea-   1-(Pyridin-3-yl)-3-(4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)thiourea-   1-(4-(1-(2,6-Dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)thiourea.

A further object of the present invention is a compound of formula I foruse as therapeutically active substance and, more particularly, for usein the treatment of cancer and, even more particularly, pancreaticcancer.

A further object of the present invention is a pharmaceuticalcomposition comprising a compound of formula I and pharmaceuticallyacceptable excipients.

A further object of the present invention is the use of a compound offormula I for the manufacture of a medicament for treating cancer and,more particularly, pancreatic cancer.

The new compounds of formula I and their pharmaceutically acceptablesalts, can be prepared by methods known in the art, for example, byprocesses described below, which processes comprise:

a) Reacting a compound of formula 1

With a compound of formula 2

Ar₁COOH  2

To a compound of formula I

wherein

A is C_(n)H_(2n), C_(n)H_(2n−2), C_(n)H_(2n−4) wherein n=4, 5, 6, 7

B is oxo (═O)

D is —CH═CH—

Ar₁ and Ar₂ are as defined in claim 1

b) Reacting a compound of formula 3

With a compound of formula 4

To a compound of formula I

wherein

A is C_(n)H_(2n), C_(n)H_(2n−2), C_(n)H_(2n−4) wherein n=4, 5, 6, 7

B is ═N—CN

D is NH

Ar₁ and Ar₂ are as defined in claim 1

c) Reacting a compound of formula 3

With a compound of formula 5

To a compound of formula I

wherein

A is C_(n)H_(2n), C_(n)H_(2n−2), C_(n)H_(2n−4) wherein n=4, 5, 6, 7

B is oxo (═O)

D is NH

Ar₁ and Ar₂ are as defined in claim 1

d) Reacting a compound of formula 3

With a compound of formula 6

Ar₂—NCS  2

To a compound of formula I

A is C_(n)H_(2n), C_(n)H_(2n−2), C_(n)H_(2n−4) wherein n=4, 5, 6, 7

B is thio (═S)

D is NH

Ar₁ and Ar₂ are as defined in claim 1

e) Reacting a compound of formula 7

With a compound of formula 2

Ar₁COOH  2

To a compound of formula I

A is C_(n)H_(2n), C_(n)H_(2n−2), C_(n)H_(2n−4) wherein n=4, 5, 6, 7

B is thio (═S), D is —CH═CH—

Ar₁ and Ar₂ are as defined in claim 1

The preparation of compounds of formula I may be carried out insequential or convergent synthetic routes. Syntheses of the compounds ofthe invention are shown under “Manufacturing Processes and Examples”below. The skills required for carrying out the reaction andpurification of the resulting products are known to those skilled in theart. The substituents and indices used in the following description ofthe processes have the significance given herein before unless otherwiseindicated.

In more detail, the compounds of formula I can be manufactured by themethods given in the examples or by analogous methods. Appropriatereaction conditions for the individual reaction steps are known to aperson skilled in the art.

Isolation and purification of the compounds and intermediates describedherein can be carried out, if desired, by any suitable separation orpurification procedure such as, for example, filtration, extraction,crystallization, column chromatography, thin-layer chromatography,thick-layer chromatography, preparative low or high-pressure liquidchromatography or a combination of these procedures. If needed, racemicmixtures of chiral compounds of formula I can be separated using chiralHPLC.

The compounds of formula I are basic and may be converted to acorresponding acid addition salt. The conversion is accomplished bytreatment with at least a stoichiometric amount of an appropriate acid,such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid,phosphoric acid and the like, and organic acids such as acetic acid,propionic acid, glycolic acid, pyruvic acid, oxalic acid, malic acid,malonic acid, succinic acid, lactic acid, malic acid, maleic acid,fumaric acid, tartaric acid, citric acid, benzoic acid, cinnamic acid,mandelic acid, camphanic acid, methanesulfonic acid, ethanesulfonicacid, p-toluenesulfonic acid, camphorsulfonic acid, salicylic acid andthe like. Typically, the free base is dissolved in an inert organicsolvent such as diethyl ether, ethyl acetate, chloroform, ethanol ormethanol and the like and the acid added thereto. The temperature ismaintained between 0° C. and 50° C. The resulting salt precipitatesspontaneously or may be brought out of solution with a less polarsolvent.

The compounds of formula I and their pharmaceutically usable additionsalts possess valuable pharmacological properties. Specifically, it hasbeen found that the compounds of the present invention, alone or incombination with other therapeutic active compounds, have an activity aschemotherapeutic agents against cancers and, more particularly,pancreatic cancers. The compounds of formula I and theirpharmaceutically usable addition salts have improved water solubilityand pharmacologic half life if compared to the benchmark compound FK866.

The compounds of formula I were investigated in accordance with the testgiven hereinafter.

The compounds of formula I and the pharmaceutically acceptable salts ofthe compounds of formula I can be used as medicaments, e.g. in the formof pharmaceutical preparations. The pharmaceutical preparations can beadministered orally, e.g. in the form of tablets, coated tablets,dragées, hard and soft gelatine capsules, solutions emulsions orsuspensions. The administration can, however, also be effected rectally,e.g. in the form of suppositories, or parenterally, e.g. in the form ofinjection solutions.

The compounds of formula I can be processed with pharmaceutically inert,inorganic or organic carriers for the production of pharmaceuticalpreparations. Lactose, corn starch or derivatives thereof, talc, stearicacids or its salts and the like can be used, for example, as suchcarriers for tablets, coated tablets, dragees and hard gelatinecapsules. Suitable carriers for soft gelatine capsules are, for example,vegetable oils, waxes, fats, semi-solid and liquid polyols and the like.Depending on the nature of the active substance no carriers are howeverusually required in the case of soft gelatine capsules. Suitablecarriers for the production of solutions and syrups are, for example,water, polyols, glycerol, vegetable oil and the like. Suitable carriersfor suppositories are, for example, natural or hardened oils, waxes,fats, semi-liquid or liquid polyols and the like.

The pharmaceutical preparations can moreover contain preservatives,solubilizers, stabilizers, wetting agents, emulsifiers, sweeteners,colorants, flavorants, salts for varying the osmotic pressure, buffers,masking agents or antioxidants. They can also contain still othertherapeutically valuable substances.

Medicaments containing a compound of formula I or a pharmaceuticallyacceptable salt thereof and a therapeutically inert carrier are also anobject of the present invention, as is a process for their production,which comprises bringing one or more compounds of formula I and/orpharmaceutically acceptable acid addition salts and, if desired, one ormore other therapeutically valuable substances into a galenicaladministration form together with one or more therapeutically inertcarriers.

The dosage can vary within wide limits and will have to be adjusted tothe individual requirements in each particular case. In the case of oraladministration, the dosage for adults can vary from about 0.01 mg toabout 1000 mg per day of a compound of general formula I or of thecorresponding amount of a pharmaceutically acceptable salt thereof. Thedaily dosage may be administered as single dose or in divided doses and,in addition, the upper limit can also be exceeded when this is found tobe appropriate by medical practitioners.

Tablet Formulation (Wet Granulation)

Mg/tablet 25 100 500 Item Ingredients 5 mg mg mg mg 1 Compound offormula I 5 25 100 500 2 Lactose Anhydrous DTG 125 105 30 150 3 Sta-RX1500 6 6 6 30 4 Mycrocristalline Cellulose 30 30 30 150 5 MagnesiumStearate 1 1 1 1 Total 167 167 167 831

Manufacturing Procedure

Mix items 1, 2, 3 and 4 and granulate with purified water.

Dry the granules at 50° C.

Pass the granules through suitable milling equipment.

Add item 5 and mix for three minutes; compress on a suitable press.

Capsule Formulation

Mg/capsule 25 100 500 Item Ingredients 5 mg mg mg mg 1 Compound offormula I 5 25 100 500 2 Hydrous Lactose 159 123 148 — 3 Corn Starch 2535 40 70 4 Talc 10 15 10 25 5 Magnesium Stearate 1 2 2 5 Total 200 200300 600

Manufacturing Procedure

Mix items 1, 2 and 3 in a suitable mixer for 30 minutes.

Add items 4 and 5 and mix for 3 minutes.

Fill into a suitable capsule

Manufacturing Process and Examples

General

All commercially available reagents were purchased from Sigma Aldrich,Fluka or Acros and used without further purification. For reactionsrequiring anhydrous conditions, dry solvents were bought (Fluka,Aldrich). All reactions were carried out under nitrogen atmosphere inoven-dried glassware with magnetic stirring. Analytical TLC (thin layerchromatography) was performed with silica gel 60 F₂₅₄ aluminum plates(Merck) with visualization by UV light and charring with aqueous KMnO₄solution, ethanolic ninhydrin solution or Pancaldi reagent. Columnchromatography was performed with 230-400 mesh, MN Kieselgel 60M silicagel (Merck) and. Infrared spectra were recorded with a Jasco FTIR-410spectrophotometer. 1H and ¹³C NMR analyses were performed with BrukerAVIII-400 spectrometer at 400 MHz and 100 MHz respectively and BrukerAMX300 spectrometer at 300 MHz and 75.4 MHz respectively at 20° C. (thepiperidine of amide show split signals in ¹³C NMR at 20° C.). Chemicalshifts are calibrated using residual solvents signals (CDCl₃: δ(H)=7.26, δ (C)=77.16; CD₃CN: δ (H)=1.94, δ (C)=118.26, 1.32) andreported in ppm. Multiplicities: s=apparent singlet, d=apparent doublet,t=apparent triplet, q=apparent quadruplet, m=multiplet, br=broad.Apparent coupling constant are given in Hz. The assignments wereconfirmed by COSY and HSQC experiments. Mass spectra (CI and LSI) wererecorded on Micromass AutoSpeQ and QTRAP spectrometers. The LSI wasperformed using thioglycerol as the matrix. HRMS spectra were recorderon Mass Spectral Facility of Institute of Chemical Sciences andEngineering (ISIC), Swiss Federal Institute of Technology, Lausanne(EPFL) and CITIUS (University of Seville), are given in m/z.

Abbreviations

Boc=(tert-Butoxy)carbonyl;

Dess-Martinreagent=1,1,1-Triacetoxy-1,1-dihydro-1,2-benziodoxol-3(1H)-one

DEAD=diethyl azodicarboxylate

DCM=dichloromethane

DIPEA=di(isopropyl)ethylamine

DIBAL=diisopropylaluminium hydride

DMF=N,N-dimethylformamide

HOBt=N-Hydroxybenzotriazole;

EDCl=1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride

EtOAc=ethyl acetate

LAH=LiAlH₄

NMM=N-methylmorpholine;

PE=petroleum ether

PyBOP=benzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate

TEA=triethylamine

TFA=trifluoroacetic acid

THF=tetrahydrofuran

TsCl=paratoluenesulfonyl chloride

FC=Flash column chromatography on silica gel, unless noted otherwise.

TLC=thin layer chromatography on silica gel.

MW=molecular weight

General Procedure for the Synthesis of FEI 56, FEI 58, FEI 62, FEI 71,FEI 74, FEI 75, FEI 95, FEI 96, FEI 97, FEI 98

4-(Piperidin-4-yl)butan-1-ol (5)

A suspension of 4-(piperidin-4-yl)butanoic acid hydrochloride (4, 9.0 g,44 mmol, MW=200.664) in dry THF (150 mL) was cooled in an ice bath.Lithium aluminium hydride (6.6 g, 173 mmol) was added in small portionsunder vigorous stirring. After the end of the adding stirring wascontinued at 20° C. for 10 min and the reaction mixture was heated underreflux for 6 h. The reaction mixture was cooled to 0° C., and 30% aq.KOH was added slowly under vigorous stirring until a white solid wasprecipitated (30 mL). After stirring at 20° C. for 1 h the suspensionwas filtered on a Cellite bed and the cake was washed with THF (50 mL).After evaporation of the solvent in vacuo, the crude was purified by FC(18/2/80 EtOAc/Et₃N/MeOH) to give 6.15 g (88.8%) of 5 (MW=157.258) asyellow oil.

¹H NMR (400 MHz, CDCl₃): δ=3.61 (t, 2H, J=6.6 Hz), 3.02 (dt, 2H, J=12.3Hz, 2.6 Hz), 2.56 (t, 2H, J=12.0 Hz), 1.70-1.63 (m, 2H), 1.58-1.50 (m,2H), 1.42-1.34 (m, 2H), 1.30-1.22 (m, 3H), 1.06 (qd, 2H, J=12.1 Hz, 4.0Hz).

(1-2) tert-Butyl 4-(4-hydroxybutyl)piperidine-1-carboxylate (6)

A solution of 4-(piperidin-4-yl)butan-1-ol (5, 1.57 g, 10 mmol) andtriethylamine (1.50 mL, 10.5 mmol) in CH₂Cl₂ (30 mL) was cooled to 0° C.Di-tert-butyl dicarbonate (2.30 g, 10.5 mmol) in CH₂Cl₂ (5 mL) was addeddropwise. After the addition, the mixture was stirred at 20° C. for 3 h(monitored by TLC). The mixture was then washed with water (30 mL) andthe organic layer concentrated in vacuo. The residue was purified by FC(4/1 PE/EtOAc) to give 6 (2.16 g, 54.7%, MW=253.345) as yellow oil.

¹H NMR (400 MHz, CDCl₃): δ=4.09 (d, 2H, J=11.9 Hz), 3.67 (t, 2H, J=6.6Hz), 2.68 (t, 2H, J=12.0 Hz), 1.70-1.63 (m, 2H), 1.61-1.54 (m, 2H), 1.47(s, 9H), 1.44-1.36 (m, 3H), 1.31-1.25 (m, 2H), 1.09 (qd, 2H, J=12.6 Hz,4.5 Hz).

(1-3) tert-Butyl4-(4-(1,3-dioxoisoindolin-2-yl)butyl)piperidine-1-carboxylate (7)

Under N₂, phthalimide (0.82 g, 5.52 mmol) and Ph₃P (1.45 g, 5.52 mmol)were dissolved in dry THF (10 mL). This solution was added to a solutionof 6 (1.2 g, 4.73 mmol) in dry THF (15 mL). The reaction mixture wasstirred at 20° C. for 10 min then cooled to 0° C. Diethylazodicarboxylate (0.87 mL, 5.52 mmol) was added dropwise at 0° C. Thenthe cooling bath was removed and the reaction mixture was stirred at 20°C. for 7 h (monitored by TLC). The solvent was evaporated in vacuo, andthe residue was purified by FC (1/10 acetone/PE) to give 7 (1.63 g,89.1%, MW=386.496) as yellow solid.

¹H NMR (400 MHz, CDCl₃): δ=7.88-7.84 (m, 2H), 7.74-7.71 (m, 2H),4.15-3.97 (m, 2H), 3.70 (t, 2H, J=7.3 Hz), 2.66 (t, 2H, J=12.3 Hz),1.72-1.62 (m, 4H), 1.47 (s, 9H), 1.41-1.33 (m, 3H), 1.32-1.26 (m, 2H),1.07 (qd, 2H, J=12.0 Hz, 4.5 Hz).

tert-Butyl 4-(4-aminobutyl)piperidine-1-carboxylate (8)

Under N₂, 7 (1.62 g, 4.19 mmol) and hydrazine hydrate (0.51 mL, 10.3mmol) were dissolved in dry ethanol (25 mL). The mixture was stirred at20° C. for 10 min and then heated under reflux (85° C.) for 2 h. Duringthe reaction a white precipitate formed as byproduct. After cooling downto 20° C., the white precipitate was filtered off and washed withadditional ethanol (25 mL). Solvent evaporation in vacuo gave a slurrythat was dissolved CH₂Cl₂ (30 mL) and a saturated aqueous solution ofK₂CO₃ (30 mL) was added giving a clear solution. The aqueous layer wasextracted with CH₂Cl₂ (15 mL, 3 times) and the combined organic extractswere washed with brine (30 mL). After drying (MgSO₄), the solvent wasevaporated in vacuo, and the residue was purified by FC (80/18/2MeOH/EtOAc/TEA) to give 0.92 g (85.6%) of 8 (MW=256.392) as yellow oil.

¹H NMR (400 MHz, CDCl₃): δ=4.18-3.95 (m, 2H), 2.78-2.58 (m, 4H),1.70-1.62 (m, 2H), 1.47 (s, 9H), 1.46-1.40 (m, 2H), 1.39-1.31 (m, 3H),1.30-1.23 (m, 2H), 1.08 (qd, 2H, J=12.1 Hz, 4.1 Hz).

(E)-N-(4-(Piperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide hydrochloride(9a) (for the preparation of FEI 56, FEI 58, FEI 62, FEI 71, FEI 74, FEI75)

Under N₂ atmosphere, HOBt hydrate (0.31 g, ca. 2.0 mmol, MW=125.12+ca.12% H₂O), EDCl (0.33 g ca. 2.1 mmol, MW=155.25) and(E)-3-(3-pyridyl)acrylic acid (0.33 g, 2.2 mmol, MW=149.137) were addedsequentially to a cooled (0° C.) solution of 8 (0.515 g. 2 mmol,MW=256.392) in dry CH₂Cl₂ (7 mL). after stirring at 0° C. for 10 minN-methylmorpholine (0.44 mL) was added drop-wise under stirring at 0° C.The mixture was then allowed to reach room temperature under stirringand stirred until completion of the reaction (monitored by TLC). Asaturated aqueous solution of NaHCO₃(15 mL) was added and stirredvigorously for 5 min. The aqueous layer was extracted with CH₂Cl₂ (5 mL,3 times). The combined organic extracts and solution were washed withbrine (50 mL) and dried (MgSO₄). The solvent was evaporated in vacuo andthe residue purified by FC (EtOAc) to give acrylamide 9 (0.643 g, 83%,MW=387.513) as a yellow oil that was used directly in the followingreaction. Solution of compound 9 (0.39 g, 1 mmol, MW=387.513) in 4MHCl/dioxane solution (1.0 mL) was stirred at 20° C. for 30 min(monitored by TLC). After solvent evaporation in vacuo, salt 9a (0.299g, 92.3%, MW=323.889) was obtained as a white solid; it was used in thenext step without purification.

¹H NMR (400 MHz, CD₃OD): δ=9.15 (d, 1H, J=1.5 Hz), 8.91 (dt, 1H, J=8.3Hz, 1.6 Hz), 8.86 (d, 1H, J=5.7 Hz), 8.17 (dd, 1H, J=8.2 Hz, 5.8 Hz),7.67 (d, 1H, J=15.8 Hz), 7.06 (d, 1H, J=15.8 Hz), 3.62 (t, 2H, J=6.1Hz), 3.45 (t, 2H, J=7.1 Hz), 3.35-3.31 (m, 3H), 3.19-3.09 (m, 2H),2.09-1.99 (m, 2H), 1.95-1.84 (m, 4H).

Yield: 0.53 g (82%), white solid, ¹H NMR (400 MHz, CD₃OD): δ=9.12 (d,1H, J=1.6 Hz), 8.90-8.83 (m, 2H), 8.15 (dd, 1H, J=8.2 Hz, 5.8 Hz), 7.67(d, 1H, J=15.8 Hz), 7.01 (d, 1H, J=15.8 Hz), 3.42-3.34 (m, 4H), 2.99(td, 2H, J=12.7 Hz, 2.3 Hz), 2.02-1.94 (m, 2H), 1.69-1.58 (m, 3H),1.50-1.34 (m, 6H).

(E)-N-(4-(1-(2,4-Dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide(FEI-56)

Under N₂ Atm., HOBt hydrate (24.3 mg, 0.15 mmol), EDCl (34.5 mg, 0.22mmol) and 2,4-dimethoxybenzoic acid (35.7 mg, 0.19 mmol, MW=182.179)were sequentially added to a cooled (0° C.) solution of compound 9a(48.8 mg, 0.15 mmol, MW=323.419) in dry CH₂Cl₂ (2 mL). The reactionmixture was stirred for 10 min and N-methylmorpholine (0.05 mL, 0.45mmol) was added at 0° C. The resulting mixture was stirred at 20° C.overnight (monitored by TLC). Saturated aqueous of NaHCO₃(5 mL) wasadded and stirred for 5 min. The aqueous layer was extracted with CH₂Cl₂(5 mL, 3 times) and the combined organic extracts were washed with brine(20 mL). After drying (MgSO₄) and evaporation of the solvent in vacuo,the residue was purified by FC (EtOAc), giving FEI-56 (47.8 mg 70.5%,MW=451.247) as white foam.

¹H NMR (400 MHz, CDCl₃): δ=8.63-8.60 (m, 1H), 8.45 (td, 1H, J=4.5 Hz,1.2 Hz), 7.65-7.60 (m, 1H), 7.49 (d, 1H, J=15.8 Hz), 7.21-7.16 (m, 1H),7.10-7.02 (m, 1H), 6.85-6.67 (m, 1H), 6.45 (d, 1H, J=15.8 Hz), 6.42-6.37(m, 1H), 6.36-6.33 (m, 1H), 4.64 (d, 1H, J=12.2 Hz), 3.72-3.66 (m, 6H),3.41 (d, 1H, J=13.0 Hz), 3.28-3.20 (m, 2H), 2.92-2.73 (m, 1H), 2.67-2.58(m, 1H), 1.68 (d, 1H, J=12.5 Hz), 1.52-1.33 (m, 4H), 1.28-1.02 (m, 5H),0.95-0.74 (m, 1H); ¹³C NMR (100 MHz, CDCl₃): δ=167.7, 165.3, 161.5,156.7, 150.1, 149.1, 136.5, 134.3, 130.9, 128.7, 123.6, 123.5, 118.8,104.8, 98.5, 55.5, 53.5, 47.7, 42.0, 39.7, 36.1, 36.0, 32.8, 32.0, 29.7,24.0; HRMS (ESI) for C₂₆H₃₃N₃O₄ [M+H]⁺ calcd: 452.2549, found: 452.2550.

FEI-58, FEI-62, FEI-71, FEI-74 and FEI 75 were prepared from salt 9a(48.8 mg, 0.15 mmol) and different carboxylic acids (Ar₁COOH, 0.18 mmol)according to the same procedure as that used to prepare FEI-56.

(E)-N-(4-(1-(2,6-Dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide(FEI-58)

Ar₁COOH=2,6-dimethoxybenzoic acid. Yield: 43.6 mg (64.4%, MW=451.247),white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.63-8.59 (m, 1H), 8.48-8.44 (m,1H), 7.67-7.62 (m, 1H), 7.49 (d, 1H, J=15.8 Hz), 7.21-7.13 (m, 2H),6.80-6.64 (m, 1H), 6.49-6.43 (m, 3H), 4.69 (d, 1H, J=12.8 Hz), 3.70 (s,3H), 3.68 (s, 3H), 3.37 (d, 1H, J=13.5 Hz), 3.27-3.20 (m, 2H), 2.88-2.82(m, 1H), 2.65 (td, 1H, J=12.6 Hz, 2.5 Hz), 1.68 (d, 1H, J=13.1 Hz),1.50-1.34 (m, 4H), 1.29-1.12 (m, 5H), 1.06-0.96 (m, 1H); ¹³C NMR (100MHz, CDCl₃): δ=165.2, 156.4, 150.1, 149.1, 136.5, 136.4, 134.3, 130.9,130.1, 123.6, 123.5, 114.8, 103.9, 55.8, 46.9, 41.7, 39.8, 36.1, 36.0,32.8, 31.9, 29.8, 24.0; HRMS (ESI) for C₂₆H₃₃N₃O₄ [M+H]⁺ calcd:452.2549, found: 452.2545.

(E)-3-(Pyridin-3-yl)-N-(4-(1-(2,4,6-trimethoxybenzoyl)piperidin-4-yl)butyl)acrylamide(FEI-62)

Ar₁COOH=2,4,6-trimethoxybenzoic acid. Yield: 42.3 mg (58.5%,MW=481.2577), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.64 (d, 1H, J=1.4Hz), 8.48 (dd, 1H, J=4.7 Hz, 1.2 Hz), 7.6t (dt, 1H, J=7.9 Hz, 1.9 Hz),7.51 (d, 1H, J=15.7 Hz), 7.22-7.18 (m, 1H), 6.44 (d, 1H, J=15.7 Hz),6.40-6.35 (m, 1H), 6.03-6.01 (m, 2H), 4.69 (d, 1H, J=13.0 Hz), 3.72 (s,3H), 3.68 (d, 6H, J=6.6 Hz), 3.42 (d, 1H, J=13.2 Hz), 3.24 (dd, 2H,J=13.4 Hz, 7.1 Hz), 2.89-2.79 (m, 1H), 2.64 (td, 1H, J=12.5 Hz, 2.3 Hz),1.68 (d, 1H, J=12.5 Hz), 1.51-1.43 (m, 3H), 1.34-1.25 (m, 2H), 1.23-1.16(m, 3H), 1.13-0.96 (m, 2H); ¹³C NMR (100 MHz, CDCl₃): δ=165.2, 161.8,157.4, 150.2, 149.2, 136.7, 134.3, 130.9, 123.6, 123.3, 121.0, 107.9,90.6, 55.8, 55.7, 55.4, 47.0, 41.8, 39.7, 36.2 (2C), 32.9, 31.9, 29.8,24.0; HRMS (ESI) for C₂₇H₃₅N₃O₅ [M+H]⁺ calcd: 482.2655, found: 482.2652.

(E)-N-(4-(1-(3-Methoxyfuran-2-carbonyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide(FEI-71)

Ar₁COOH=3-methoxyfuran-2-carboxylic acid. Yield: 40 mg (64.8%,MW=411.2158), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.74-8.63 (m, 1H),8.55-8.47 (m, 1H), 7.70 (d, 1H, J=7.8 Hz), 7.53 (d, 1H, J=15.8 Hz), 7.27(d, 1H, J=1.9 Hz), 7.25-7.21 (m, 1H), 6.47 (d, 1H, J=15.8 Hz), 6.27 (d,1H, J=1.9 Hz), 6.25 (brs, 1H, N—H), 4.52-4.27 (m, 1H), 4.09-3.86 (m,1H), 3.77 (s, 3H), 3.32 (q, 2H, J=6.0 Hz), 2.99-2.59 (m, 2H), 1.69-1.61(m, 2H), 1.53-1.46 (m, 2H), 1.35-1.27 (m, 2H), 1.24-1.18 (m, 3H), 1.11(qd, 2H, J=12.3 Hz, 3.8 Hz); ¹³C NMR (100 MHz, CDCl₃): δ=165.2, 159.8,150.2, 149.6, 149.0, 143.2, 136.9, 134.3, 131.0, 123.8, 123.6, 123.2,102.0, 58.7, 47.3, 43.1, 39.8, 36.1, 36.0, 33.0, 31.9, 29.8, 24.0; HRMS(ESI) for C₂₃H₂₉N₃O₄ [M+H]⁺ calcd: 412.2236, found: 412.2239.

(E)-N-(4-(1-(Isoxazole-5-carbonyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide(FEI-74)

Ar₁COOH=1,2-oxazole-5 carboxylic acid. Yield: 46.5 mg (81.1%,MW=382.2005), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.67 (s, 1H), 8.50(d, 1H, J=4.1 Hz), 8.23 (d, 1H, J=1.7 Hz), 7.71 (d, 1H, J=8.0 Hz), 7.55((d, 1H, J=15.7 Hz), 7.24 (dd, 1H, J=7.7 Hz, 4.9 Hz), 6.64 (d, 1H, J=1.7Hz), 6.42 (d, 1H, J=15.7 Hz), 5.92 (brs, 1H, N—H), 4.56 (d, 1H, J=13.3Hz), 4.01 (d, 1H, J=13.3 Hz), 3.33 (q, 2H, J=6.4 Hz), 3.03 (t, 1H,J=12.0 Hz), 2.70 (td, 1H, J=12.7 Hz, 2.0 Hz), 1.73 (t, 2H, J=17.2 Hz),1.54-1.47 (m, 3H), 1.37-1.29 (m, 2H), 1.27-1.22 (m, 2H), 1.18-1.11 (m,2H); ¹³C NMR (100 MHz, CDCl₃): δ=167.1, 164.1, 156.9, 150.3, 150.1,149.1, 137.3, 134.4, 130.7, 123.7, 122.9, 106.8, 47.0, 43.2, 39.7, 36.0,35.9, 32.9, 31.8, 29.9, 23.9; HRMS (ESI) for C₂₁H₂₆N₄₀₃ [M+H]⁺ calcd:382.2083, found: 382.2073.

(E)-N-(4-(1-(4-Formyl-2,6-dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide (FEI-75)

Ar₁COOH=4-formyl-2,6-dimethoxybenzoic acid. Yield: 38.4 mg (53.4%,MW=479.2420), white foam. ¹H NMR (400 MHz, CDCl₃): δ=9.86 (s, 1H), 8.65(s, 1H), 8.49 (dd, 1H, J=4.7 Hz, 1.1 Hz), 7.69 (d, 1H, J=7.8 Hz), 7.53(d, 1H, J=15.6 Hz), 7.22 (dd, 1H, J=7.7 Hz, 4.9 Hz), 7.00 (d, 2H, J=3.3Hz), 6.40 (d, 1H, J=15.6 Hz), 5.96 (brs, 1H, N—H), 4.69 (d, 1H, J=13.0Hz), 3.81 (s, 3H), 3.79 (s, 3H), 3.34-3.26 (m, 3H), 3.28 (td, 1H, J=13.0Hz, 2.4 Hz), 2.68 (td, 1H, J=12.8 Hz, 2.4 Hz), 1.77-1.68 (m, 2H),1.53-1.44 (m, 3H), 1.35-1.26 (m, 2H), 1.24-1.19 (m, 2H), 1.16-0.97 (m,2H); ¹³C NMR (100 MHz, CDCl₃): δ=191.4, 165.2, 163.8, 157.3, 150.2,149.1, 137.9, 137.2, 134.4, 130.7, 123.7, 122.9, 120.8, 105.3, 56.1,46.9, 41.7, 39.7, 36.1, 36.0, 32.8, 31.8, 29.8, 24.0; HRMS (ESI) forC₂₇H₃₃N₃O₅ [M+H]⁺ calcd: 480.2498, found: 480.2500.

(E)-N-(4-(Piperidin-4-yl)butyl)-3-(pyridazin-4-yl)acrylamidehydrochloride (9d) (for the preparation of FEI 95, FEI 96, FEI 97, FEI98)

Salt 9d was prepared from amine 8 (0.26 g, 1.0 mmol) and(E)-3-(pyridazin-4-yl)acrylic acid (0.18 g, 1.2 mmol) according to thesame procedure as that used to prepare 9a (2 steps).

Yield: 0.25 g (77%, MW=323.874), white solid. ¹H NMR (400 MHz, CD₃OD):δ=9.44-9.41 (m, 1H), 9.28 (dd, 1H, J=5.4 Hz, 0.7 Hz), 7.85 (dd, 1H,J=5.3 Hz, 2.2 Hz), 7.42 (d, 1H, J=16.0 Hz), 7.01 (d, 1H, J=16.0 Hz),3.28-3.15 (m, 4H), 2.88-2.75 (m, 2H), 1.84-1.72 (m, 2H), 1.54-1.40 (m,3H), 1.36-1.18 (m, 6H).

FEI 95-98 were prepared from salt 9d (48.6 mg, 0.15 mmol) and differentcarboxylic acids Ar₁COOH (0.18 mmol) according to the same procedure asthat used to prepare FEI-56.

(E)-N-(4-(1-Benzoylpiperidin-4-yl)butyl)-3-(pyridazin-4-yl)acrylamide(FEI-95)

Ar₁COOH=benzoic acid. Yield: 47.8 mg (81.2%, MW=392.2212), white foam.¹H NMR (400 MHz, CDCl₃): δ=9.19 (s, 1H), 9.10 (d, 1H, J=4.9 Hz), 7.43(d, 1H, J=15.8 Hz), 7.36 (dd, 1H, J=5.1 Hz, 1.7 Hz), 7.33-7.28 (m, 5H),7.10-6.97 (m, 1H, N—H), 6.80 (dd, 1H, J=15.8 Hz, 4.6 Hz), 4.66-4.54 (m,1H), 3.71-3.57 (m, 1H), 3.28 (q, 2H, J=6.8 Hz), 2.90 (t, 1H, J=10.4 Hz),2.67 (t, 1H, J=9.8 Hz), 1.76-1.51 (m, 2H), 1.51-1.41 (m, 3H), 1.34-1.25(m, 2H), 1.23-1.18 (m, 2H), 1.14-0.98 (m, 2H); ¹³C NMR (100 MHz, CDCl₃):δ=170.4, 164.2, 151.7, 149.3, 136.3, 133.8, 133.5, 129.6, 128.5, 128.4,126.7, 124.0, 48.1, 42.6, 39.8, 36.1, 36.0, 32.9, 31.0, 29.6, 24.0; HRMS(ESI) for C₂₃H₂₈N₄O₂ [M+H]⁺ calcd: 393.2285, found: 393.2283.

(E)-N-(4-(1-(Furan-2-carbonyl)piperidin-4-yl)butyl)-3-(pyridazin-4-yl)acrylamide(FEI-96)

Ar₁COOH=furan-2-carboxylic acid. Yield: 45.6 mg (79.5%, MW=382.2005),white foam. ¹H NMR (400 MHz, CDCl₃): δ=9.24 (s, 1H), 9.13 (s, 1H), 7.46(d, 1H, J=15.8 Hz), 7.43-7.38 (m, 2H), 6.91-6.86 (m, 1H, N—H), 6.85-6.80(m, 2H), 6.41-6.38 (m, 1H), 4.55-4.27 (m, 2H), 3.33 (q, 2H, J=6.7 Hz),3.08-2.52 (m, 2H), 1.69 (d, 2H, J=12.8 Hz), 1.55-1.44 (m, 3H), 1.36-1.28(m, 2H), 1.25-1.20 (m, 2H), 1.12 (qd, 2H, J=12.2 Hz, 3.3 Hz); ¹³C NMR(100 MHz, CDCl₃): δ=164.2, 159.3, 151.9, 149.3, 148.8, 143.6, 134.1,133.4, 128.6, 124.0, 115.6, 111.1, 46.7, 43.4, 39.8, 36.1, 36.0, 32.9,31.0, 29.6, 24.0; HRMS (ESI) for C₂₁H₂₆N₄O₃ [M+H]⁺ calcd: 383.20777,found: 383.20768.

(E)-3-(Pyridazin-4-yl)-N-(4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)acrylamide(FEI-97)

Ar₁COOH=thiophene-2-carboxylic acid. Yield: 45.8 mg (76.7%,MW=398.1776), white foam. ¹H NMR (400 MHz, CDCl₃): δ=9.22 (s, 1H), 9.12(s, 1H), 7.46 (d, 1H, J=15.7 Hz), 7.41-7.37 (m, 1H), 7.36 (dt, 1H, J=5.0Hz, 1.1 Hz), 7.19 (t, 1H, J=3.6 Hz), 6.96 (t, 1H, J=4.1 Hz), 6.77 (d,1H, J=15.7 Hz), 6.74-6.71 (m, 1H, N—H), 4.49-4.13 (m, 2H), 3.32 (q, 2H,J=6.4 Hz), 2.96-2.79 (m, 2H), 1.68 (d, 2H, J=12.6 Hz), 1.54-1.42 (m,3H), 1.36-1.28 (m, 2H), 1.26-1.20 (m, 2H), 1.11 (qd, 2H, J=12.2 Hz, 3.7Hz); ¹³C NMR (100 MHz, CDCl₃): δ=164.1, 163.5, 151.8, 149.3, 137.3,134.2, 133.4, 128.5, 128.3, 126.7, 124.0, 124.0, 46.7, 43.4, 39.8, 36.1,36.0, 32.9, 31.0, 29.7, 24.0; HRMS (ESI) for C₂₁H₂₆N₄O₂S [M+H]⁺ calcd:399.18492, found: 399.18484.

(E)-N-(4-(1-(2,6-Dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridazin-4-yl)acrylamide(FEI-98)

Ar₁COOH=2,6-dimethoxybenzoic acid. Yield: 44.3 mg (65.3%, MW=452.2424),white foam. ¹H NMR (400 MHz, CDCl₃): δ=9.15 (s, 1H), 9.08 (d, 1H, J=5.3Hz), 7.40 (d, 1H, J=15.8 Hz), 7.34 (dd, 1H, J=5.3 Hz, 2.3 Hz), 7.21-7.12(m, 2H), 6.79 (d, 1H, J=15.8 Hz), 6.47 (d, 2H, J=8.4 Hz), 4.70 (d, 1H,J=13.2 Hz), 3.70 (s, 3H), 3.69 (s, 3H), 3.38 (d, 1H, J=13.5 Hz), 3.24(q, 2H, J=6.2 Hz), 2.86 (td, 1H, J=12.7 Hz, 2.3 Hz), 2.67 (td, 1H,J=12.8 Hz, 2.7 Hz), 1.71 (d, 1H, J=12.6 Hz), 1.50-1.36 (m, 4H),1.32-1.23 (m, 2H), 1.22-1.15 (m, 2H), 1.13-1.0 (m, 2H); ¹³C NMR (100MHz, CDCl₃): δ=165.4, 164.3, 156.6, 151.6, 149.3, 133.6, 133.5, 130.2,128.9, 123.9, 114.7, 103.9, 55.8, 47.0, 41.8, 39.8, 36.1, 36.0, 32.9,31.9, 29.6, 24.0; HRMS (ESI) for C₂₅H₃₂N₄O₄ [M+H]⁺ calcd: 453.24963,found: 453.24959.

General Procedure for the Synthesis of FK-866 Analogues FEI 80, 81, 82,83, 85.

tert-Butyl (E)-4-(4-ethoxy-4-oxobut-2-en-1-yl)piperidine-1-carboxylate(11)

tert-Butyl 4-(2-oxoethyl)piperidine-1-carboxylate (10, 1.14 g, 5.0 mmol,MW=227.317, Aldrich or Fluochem, CAS 142374-19-4) was dissolved inCH₂Cl₂ (20 mL), (carbethoxymethylene)triphenylphosphorane (3.14 g, 9.0mmol) was added in small portions under vigorous stirring at 0° C. Themixture stirred at 20° C. for 3 h, then concentrated, the residue waspurified by FC (5/1 PE/EtOAc) to give 1.39 g (93.3%) of 11 (MW=297.399)as colorless oil. ¹H NMR (400 MHz, CDCl₃): δ=6.94 (dt, 1H, J=15.6 Hz,7.7 Hz), 5.84 (dt, 1H, J=15.6 Hz, 1.4 Hz), 4.20 (q, 2H, J=7.0 Hz),4.16-4.01 (m, 2H), 2.69 (t, 2H, J=11.4 Hz), 2.17 (t, 2H, J=7.5 Hz),1.73-1.64 (m, 2H), 1.62-1.54 (m, 1H), 1.47 (s, 9H), 1.31 (t, 3H, J=7.4Hz), 1.15 (qd, 2H, J=11.8 Hz, 3.0 Hz).

tert-Butyl (E)-4-(4-hydroxybut-2-en-1-yl)piperidine-1-carboxylate (12)

1M DIBAL in CH₂Cl₂ (10 mL) added slowly to ester 11 (1.39 g, 4.68 mmol)in CH₂Cl₂ (10 mL) under nitrogen atmosphere at −78° C. over 20 min. Themixture keep stirred at −78° C. for 40 min (monitored by TLC), andmethanol (2.0 mL) was added drop-wise to quench DIBAL. The cold solutionwas further stirred for 10 min before pouring into saturated sodium,potassium tartrate salt solution (30 mL). The mixture was vigorouslystirred at 20° C. for 3 h until it turned clear. The organic phase wascollected and dried, concentrated to give 1.17 g (97.9%) of alcohol 12(MW=255.361) as colorless oil, which was used in the next step withoutpurification. ¹H NMR (400 MHz, CDCl₃): δ=5.70-5.65 (m, 2H), 4.18-4.01(m, 4H), 2.69 (t, 2H, J=12.6 Hz), 2.02 (t, 2H, J=5.6 Hz), 1.72-1.62 (m,3H), 1.47 (s, 9H), 1.11 (qd, 2H, J=12.2 Hz, 3.9 Hz).

tert-Butyl(E)-4-(4-(1,3-dioxoisoindolin-2-yl)but-2-en-1-yl)piperidine-1-carboxylate(13)

Compound 13 (MW=384.508) was prepared from 12 (0.75 g, 2.94 mmol)according to the same procedure as that used to prepare 7, yield: 0.98 g(86.7%), white solid. ¹H NMR (400 MHz, CDCl₃): δ=7.87 (dd, 2H, J=5.5 Hz,3.1 Hz), 7.74 (dd, 2H, J=5.5 Hz, 3.0 Hz), 5.77-5.67 (m, 1H), 5.58-5.49(m, 1H), 4.26 (dd, 2H, J=6.2 Hz, 0.7 Hz), 4.17-3.95 (m, 2H), 2.67 (t,2H, J=10.6 Hz), 1.98 (t, 2H, J=7.0 Hz), 1.67-1.61 (m, 2H), 1.49-1.41 (m,1H), 1.47 (s, 9H), 1.06 (qd, 2H, J=12.0 Hz, 3.0 Hz).

tert-Butyl (E)-4-(4-aminobut-2-en-1-yl)piperidine-1-carboxylate (14)

Primary amine 14 (MW=254.376) was prepared from 13 (0.8 g, 2.08 mmol)according to the same procedure as that used to prepare 8, yield: 0.45 g(85%), yellow oil. It was used directly in the next step withoutpurification.

(E)-N-((E)-4-(Piperidin-4-yl)but-2-en-1-yl)-3-(pyridin-3-yl)acrylamidehydrochloride (15)

Salt 15 (MW=321.872) was prepared from amine 14 (0.45 g, 1.76 mmol) and(E)-3-(pyridin-3-yl)acrylic acid (0.31 g, 2.10 mmol) according to thesame procedure as that used to prepare 9a (2 steps). Yield: 0.48 g(84.7%), white solid. ¹H NMR (400 MHz, CD₃OD): δ=9.01 (d, 1H, J=1.6 Hz),8.77 (dt, 1H, J=8.2 Hz, 1.4 Hz), 8.74 (d, 1H, J=5.6 Hz), 8.04 (dd, 1H,J=8.2 Hz, 5.8 Hz), 7.56 (d, 1H, J=15.8 Hz), 6.92 (d, 1H, J=15.8 Hz),5.63-5.44 (m, 2H), 3.81 (d, 2H, J=5.6 Hz), 3.28 (dt, 2H, J=12.6 Hz, 1.8Hz), 2.87 (td, 2H, J=12.6 Hz, 2.5 Hz), 1.99 (t, 2H, J=6.3 Hz), 1.89-1.81(m, 2H), 1.65-1.53 (m, 1H), 1.37-1.23 (m, 2H).

FEI 80, 81, 82, 83, 85 were prepared from salt 15 (48.2 mg, 0.15 mmol)and different carboxylic acids Ar₁COOH (0.2 mmol) using the sameprocedure as that applied for the preparation of FEI-56.

(E)-N-((E)-4-(1-Benzoylpiperidin-4-yl)but-2-en-1-yl)-3-(pyridin-3-yl)acrylamide(FEI-80)

Ar₁COOH=benzoic acid, Yield: 48.5 mg (83%, MW=389.2103), white foam. ¹HNMR (400 MHz, CDCl₃): δ=8.74-8.60 (m, 1H), 8.53-8.44 (m, 1H), 7.68 (d,1H, J=7.8 Hz), 7.53 (d, 1H, J=15.8 Hz), 7.34-7.28 (m, 5H), 7.25-7.21 (m,1H), 6.44 (d, 1H, J=15.8 Hz), 6.27-6.22 (m, 1H, N—H), 5.58-5.40 (m, 2H),4.67-4.57 (m, 1H), 3.87 (t, 2H, J=5.6 Hz), 3.72-3.59 (m, 1H), 2.95-2.80(m, 1H), 2.72-2.61 (m, 1H), 1.94 (t, 2H, J=6.8 Hz), 1.76-1.66 (m, 1H),1.58-1.45 (m, 2H), 1.25-1.04 (m, 2H); ¹³C NMR (100 MHz, CDCl₃): δ=170.3,165.0, 150.2, 149.0, 137.2, 136.3, 134.4, 130.8, 129.8, 129.5, 128.4,127.7, 126.8, 123.8, 122.9, 48.0, 42.4, 41.6, 39.1, 36.2, 32.5, 31.6;HRMS (ESI) for C₂₄H₂₇N₃O₂ [M+H]⁺ calcd: 390.2181, found: 390.2186.

(E)-N-((E)-4-(1-(2,6-Dimethoxybenzoyl)piperidin-4-yl)but-2-en-1-yl)-3-(pyridin-3-yl)acrylamide(FEI-81)

Ar₁COOH=2,6-dimethoxybenzoic acid. Yield: 40.8 mg (60.5%, MW=449.2315),white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.75-8.70 (m, 1H), 8.59-8.55 (m,1H), 7.76 (d, 1H, J=7.4 Hz), 7.62 (d, 1H, J=15.7 Hz), 7.32-7.23 (m, 2H),6.57-6.51 (m, 3H), 6.34 (brs, 1H, N—H), 5.63 (dt, 1H, J=15.7 Hz, 6.7Hz), 5.52 (dt, 1H, J=15.0 Hz, 5.5 Hz), 4.79 (d, 1H, J=12.5 Hz), 3.95 (t,2H, J=5.3 Hz), 3.79 (d, 6H, J=7.9 Hz), 3.47 (d, 1H, J=12.5 Hz), 2.90 (t,1H, J=12.0 Hz), 2.75 (t, 1H, J=12.3 Hz), 2.0 (t, 2H, J=5.9 Hz),1.81-1.74 (m, 1H), 1.60-1.52 (m, 2H), 1.34-1.11 (m, 2H); ¹³C NMR (100MHz, CDCl₃): δ=165.2, 156.6, 150.3, 149.2, 137.2, 134.3, 131.0, 130.8,130.1, 127.5, 124.7, 123.7, 123.0, 114.9, 103.9, 55.8, 46.9, 41.6, 41.5,39.2, 36.3, 32.5, 31.6; HRMS (ESI) for C₂₆H₃₁N₃O₄ [M+H]⁺ calcd:450.2393, found: 450.2388.

(E)-3-(Pyridin-3-yl)-N-((E)-4-(1-(2,4,6-trimethoxybenzoyl)piperidin-4-yl)but-2-en-1-yl)acrylamide(FEI-82)

Ar₁COOH=2,4,6-trimethoxybenzoic acid. Yield: 42.2 mg (58.7%,MW=479.2420), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.74-8.69 (m, 1H),8.56 (d, 1H, J=3.6 Hz), 7.75 (d, 1H, J=7.5 Hz), 7.61 (d, 1H, J=15.6 Hz),7.33-7.26 (m, 1H), 6.54 (d, 1H, J=15.6 Hz), 6.45 (brs, 1H, N—H),6.14-6.09 (m, 2H), 5.62 (dt, 1H, J=15.1 Hz, 6.4 Hz), 5.52 (dt, 1H,J=15.2 Hz, 5.2 Hz), 4.76 (d, 1H, J=12.5 Hz), 3.94 (t, 2H, J=4.7 Hz),3.80 (s, 3H), 3.76 (d, 6H, J=7.8 Hz), 3.51 (d, 1H, J=12.6 Hz), 2.92 (t,1H, J=11.8 Hz), 2.73 (t, 1H, J=12.0 Hz), 1.99 (t, 2H, J=6.0 Hz),1.79-1.72 (m, 1H), 1.60-1.50 (m, 2H), 1.25-1.09 (m, 2H); ¹³C NMR (100MHz, CDCl₃): δ=165.3, 165.0, 161.8, 157.7, 157.5, 150.2, 149.2, 137.0,134.3, 130.9, 130.8, 127.5, 123.6, 123.1, 90.6, 55.8, 55.4, 46.9, 41.6,41.5, 39.2, 36.3, 32.5, 31.6; HRMS (ESI) for C₂₇H₃₃N₃O₅ [M+H]⁺ calcd:480.2498, found: 480.2491.

(E)-N-((E)-4-(1-(Furan-2-carbonyl)piperidin-4-yl)but-2-en-1-yl)-3-(pyridin-3-yl)acrylamide(FEI-83)

Ar₁COOH=furan-2-carboxylic acid. Yield: 45.7 mg (80.3%, MW=379.1896),white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.78-8.71 (m, 1H), 8.61-8.55 (m,1H), 7.78 (d, 1H, J=7.6 Hz), 7.64 (d, 1H, J=15.8 Hz), 7.48 (s, 1H),7.34-7.29 (m, 1H), 6.94 (d, 1H, J=3.2 Hz), 6.54 (d, 1H, J=15.8 Hz),6.49-6.45 (m, 1H), 6.27-6.17 (m, 1H, N—H), 5.64 (dt, 1H, J=15.3 Hz, 6.9Hz), 5.54 (dt, 1H, J=15.3 Hz, 5.8 Hz), 4.60-4.42 (m, 2H), 3.99 (t, 2H,J=5.3 Hz), 3.13-2.60 (m, 2H), 2.03 (t, 2H, J=6.6 Hz), 1.76 (d, 2H,J=12.6 Hz), 1.33-1.18 (m, 3H); ¹³C NMR (100 MHz, CDCl₃): δ=164.9, 159.2,150.3, 149.0, 148.1, 143.5, 137.3, 134.4, 130.9, 130.8, 127.7, 123.0,122.8, 115.7, 111.1, 47.1, 42.4, 41.6, 39.1, 36.2, 32.4, 32.0; HRMS(ESI) for C₂₂H₂₅N₃O₃ [M+H]⁺ calcd: 380.1974, found: 380.1973.

(E)-N-((E)-4-(1-(Furan-3-carbonyl)piperidin-4-yl)but-2-en-1-yl)-3-(pyridin-3-yl)acrylamide(FEI-84)

Ar₁COOH=furan-3-carboxylic acid. Yield: 44.3 mg (77.9%, MW=379.1896),white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.71-8.61 (m, 1H), 8.52-8.46 (m,1H), 7.70 (d, 1H, J=7.6 Hz), 7.69 (s, 1H), 7.55 (d, 1H, J=15.7 Hz), 7.34(s, 1H), 7.25-7.21 (m, 1H), 6.45 (s, 1H), 6.44 (d, 1H, J=15.7 Hz),6.23-6.16 (m, 1H, N—H), 5.56 (dt, 1H, J=15.2 Hz, 6.8 Hz), 5.46 (dt, 1H,J=15.4 Hz, 5.7 Hz), 4.65-4.36 (m, 1H), 4.16-4.94 (m, 1H), 3.90 (t, 2H,J=5.1 Hz), 3.04-2.56 (m, 2H), 1.95 (t, 2H, J=6.4 Hz), 1.66 (d, 2H,J=12.0 Hz), 1.56-1.47 (m, 1H), 1.13-1.01 (m, 2H); ¹³C NMR (100 MHz,CDCl₃): δ=164.9, 163.7, 150.3, 149.1, 143.1, 142.6, 137.4, 134.4, 130.8,130.7, 127.7, 123.7, 122.6, 121.3, 110.1, 47.5, 42.5, 41.6, 39.0, 36.2,32.4, 31.7; HRMS (ESI) for C₂₂H₂₅N₃O₃ [M+H]⁺ calcd: 380.1974, found:380.1972.

(E)-3-(Pyridin-3-yl)-N-((E)-4-(1-(thiophene-2-carbonyl)piperidin-4-yl)but-2-en-1-yl)acrylamide(FEI-85)

Ar₁COOH=thiophene-2-carboxylic acid. Yield: 44.6 mg (75.2%,MW=395.1667), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.68-8.62 (m, 1H),8.48 (dd, 1H, J=4.6 Hz, 1.1 Hz), 7.68 (dt, 1H, J=7.9 Hz, 1.7 Hz), 7.54(d, 1H, J=15.7 Hz), 7.35 (dd, 1H, J=5.0 Hz, 1.1 Hz), 7.21 (dd, 1H, J=7.9Hz, 4.8 Hz), 7.18 (dd, 1H, J=3.6 Hz, 1.0 Hz), 6.95 (dd, 1H, J=5.0 Hz,3.7 Hz), 6.47 (d, 1H, J=15.7 Hz), 6.40-6.35 (m, 1H, N—H), 5.55 (dt, 1H,J=15.2 Hz, 7.1 Hz), 5.45 (dt, 1H, J=15.5 Hz, 5.7 Hz), 4.45-4.22 (m, 2H),3.89 (t, 2H, J=5.7 Hz), 2.91-2.74 (m, 2H), 1.95 (t, 2H, J=6.7 Hz), 1.67(d, 2H, J=12.6 Hz), 1.58-1.48 (m, 1H), 1.17-1.06 (m, 2H); ¹³C NMR (100MHz, CDCl₃): δ=164.9, 163.5, 150.3, 149.1, 137.4, 137.2, 134.4, 130.7,130.6, 128.5, 128.3, 127.8, 126.6, 123.7, 123.0, 47.5, 42.5, 41.6, 39.0,36.1, 32.4, 32.0; HRMS (ESI) for C₂₂H₂₅N₃O₂S [M+H]⁺ calcd: 396.1746,found: 396.1746.

General Procedure for the Synthesis of FEI 154, FEI 155, FEI 158, FEI159, FEI 162, FEI 164, FEI 166, FEI 167, FEI 168, FEI 170, FEI 171.

2-(4-(Piperidin-4-yl)butyl)isoindoline-1,3-dione hydrochloride (20)

Salt 20 was prepared from tert-butyl4-(4-(1,3-dioxoisoindolin-2-yl)butyl)piperidine-1-carboxylate (7, 4.3 g,11.1 mmol, MW=386.496) according to the same procedure as that used toprepare 9a from 9. (hydrolysis in HCl/dioxane). Yield: 3.4 g (94.5%,MW=323.838), white solid. ¹H NMR (400 MHz, CDCl₃): δ=7.90-7.84 (m, 2H),7.77-7.72 (m, 2H), 3.70 (t, 2H, J=7.1 Hz), 3.59-3.36 (m, 2H), 3.04-2.74(m, 2H), 1.99-1.83 (m, 2H), 1.71-1.56 (m, 6H), 1.42-1.33 (m, 3H).

(3-2a) (4-(4-Aminobutyl)piperidin-1-yl)(phenyl)methanone (21a)

A solution of piperidine salt 20 (0.65 g, 2.0 mmol) in CH₂Cl₂ (10 mL)was cooled to 0° C. Et₃N (0.9 mL, ca. 6 mmol) and benzoyl chloride(0.281 g, 2.0 mmol, Ar₁COCl) were added portion-wise in succession understirring. at 0° C. The mixture was allowed to reach 20° C. and wasstirred at this temperature for 3 h. A saturated aqueous solution ofNaHCO₃ (30 mL) was added and the mixture stirred vigorously at 20° C.for 10 min. The aqueous layer was extracted with CH₂Cl₂(20 mL, 3 times).The combined organic layers were washed with brine (50 mL) and dried(MgSO₄). Solvent evaporation in vacuo gave a crude benzamide that wasadded under N₂ atmosphere to a stirred solution of hydrazine hydrate(0.25 mL, ca. 5 mmol) in ethanol (10 mL) at 20° C. After stirring at 20°C. 10 min the mixture was heated under reflux for 2 h. After cooling to20° C., the white precipitate was filtered off and washed with ethanol(15 mL). The ethanolic solutions were combined and the solventevaporated in vacuo. The residue was taken in CH₂Cl₂ (20 mL) and asaturated aqueous solution of K₂CO₃ (20 mL). Vigorous stirring for 10min gave two clear phases. The aqueous phase was extracted with CH₂Cl₂(10 mL, 3 times). The combined organic phases were washed with brine (30mL) and dried (MgSO₄). After solvent evaporation in vacuo the residuewas purified by FC (80/18/2 MeOH/EtOAc/Et₃N). Yield (two steps): 0.48 g(92%, MW=260.382), yellow oil. ¹H NMR (400 MHz, CDCl₃): δ=7.44-7.37 (m,5H), 4.80-4.66 (m, 1H), 3.83-3.68 (m, 1H), 2.98 (t, 1H, J=12.4 Hz),2.83-2.66 (m, 3H), 1.90-1.78 (m, 1H), 1.69-1.51 (m, 4H), 1.42-1.25 (m,4H), 1.23-1.05 (m, 2H).

(4-(4-Aminobutyl)piperidin-1-yl)(furan-2-yl)methanone (21b)

Amide 21b was prepared from amine 20 (0.65 g, 2.0 mmol) and 2-furoylchloride (0.26 g, 2.0 mmol) according to the same procedure as that usedto prepare 21a.

Yield: 0.43 g (86%, two steps), yellow oil. The spectral data for thiscompound are the same as those described for compound 41c further below.

(4-(4-Aminobutyl)piperidin-1-yl)(thiophen-2-yl)methanone (21c)

Amide 21c was prepared from amine 20 (0.65 g, 2.0 mmol) andthiophene-2-carbonyl chloride (0.29 g, 2.0 mmol) according to the sameprocedure as that used to prepare 21a. Yield: 0.43 g (81%, two steps),yellow oil. The spectral data for this compound are the same as thosedescribed for compound 41b further below.

(3-2d) (4-(4-Aminobutyl)piperidin-1-yl)(2,6-dimethoxyphenyl)methanone(21d)

Amide 21d was prepared from amine 20 (0.64 g, 2.0 mmol) and2,6-dimethoxybenzoyl chloride (0.4 g, 2.0 mmol) according to the sameprocedure as that used to prepare 21a. Yield: 0.45 g (70.3%, two steps),yellow oil. The spectral data for this compound are the same as thosedescribed for compound 41d further below.

(E)-1-(4-(1-Benzoylpiperidin-4-yl)butyl)-2-cyano-3-(pyridin-4-yl)guanidine(FEI-154)

Step I): A solution of amine 21a (48.0 mg, 0.15 mmol), phenyl(Z)—N′-cyano-N-(pyridin-3-yl)carbamimidate (35.7 mg, 0.15 mmol) andtriethylamine (20.8 □L, 0.15 mmol) in acetonitrile (2 mL) was stirred at20° C. for 36 h (monitored by TLC). After the end of the reaction, thevolatiles were evaporated completely under reduced pressure. The residuewas purified by FC (EtOAc/MeOH=5/1) to give 38.6 mg (55%) of FEI-154 aswhite foam. Yield: 37.5 mg (61.8%, MW=404.518), white foam. ¹H NMR (400MHz, CDCl₃): δ=8.36-8.32 (m, 2H), 7.36-7.29 (m, 3H), 7.28-7.25 (m, 2H),7.14-7.08 (m, 2H), 6.02 (t, 1H, J=5.2 Hz), 4.57 (d, 1H, J=8.3 Hz), 3.65(d, 1H, J=10.6 Hz), 3.30 (q, 2H, J=6.2 Hz), 2.91 (t, 1H, J=11.4 Hz),2.68 (t, 1H, J=11.4 Hz), 1.74-1.68 (m, 1H), 1.56-1.42 (m, 4H), 1.29-1.18(m, 4H), 1.12-0.99 (m, 2H); ¹³C NMR (100 MHz, CDCl₃): δ=170.5, 157.5,150.2, 145.2, 136.0, 129.8, 128.6, 126.7, 116.9, 115.5, 48.2, 42.7,42.5, 36.1, 35.9, 33.0, 31.8, 29.5, 23.7; HRMS (ESI) for C₂₃H₂₈N₆O[M+H]⁺ calcd: 405.2403, found: 405.2405.

(E)-2-Cyano-1-(4-(1-(2,6-dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridin-4-yl)guanidine(FEI-155)

Obtained from amine 21d (48.0 mg, 0.15 mmol) and phenyl(Z)—N′-cyano-N-(pyridin-4-yl)carbamimidate (35.7 mg, 0.15 mmol)according to the same procedure as that used to prepare FEI-154. Yield:39.8 mg (57%, MW=464.57), white foam. ¹H NMR (400 MHz, CDCl₃):δ=8.38-8.32 (m, 2H), 7.30 (t, 1H, J=8.5 Hz), 7.25-7.19 (m, 2H), 6.59(dd, 2H, J=8.3 Hz, 6.5 Hz), 4.71 (d, 1H, J=13.0 Hz), 3.79 (s, 3H), 3.76(s, 3H) 3.48-3.40 (m, 3H), 2.98 (dt, 1H, J=12.6 Hz, 2.0 Hz), 2.78 (dt,1H, J=12.8 Hz, 2.7 Hz), 1.85 (d, 1H, J=12.8 Hz), 1.63-1.53 (m, 4H),1.42-1.27 (m, 4H), 1.15 (qd, 2H, J=13.2 Hz, 3.3 Hz); ¹³C NMR (100 MHz,CDCl₃): δ=165.6, 157.2, 156.4, 149.7, 145.9, 130.5, 116.6, 115.0, 114.0,103.9, 55.7, 47.1, 42.5, 42.4, 41.8, 35.9, 32.8, 31.8, 29.5, 23.7; HRMS(ESI) for C₂₅H₃₂N₆O₃ [M+H]⁺ calcd: 465.2614, found: 465.2608.

(E)-2-Cyano-1-(4-(1-(furan-2-carbonyl)piperidin-4-yl)butyl)-3-(pyridin-4-yl)guanidine(FEI-158)

Obtained from amine 21b (37.5 mg, 0.15 mmol) and phenyl(Z)—N′-cyano-N-(pyridin-4-yl)carbamimidate (35.7 mg, 0.15 mmol)according to the same procedure as that used to prepare FEI-154. Yield:37.7 mg (63.7%, MW=394.479), white foam. ¹H NMR (400 MHz, CDCl₃):δ=8.57-8.47 (m, 2H), 7.52-7.48 (m, 1H), 7.28-7.24 (m, 2H), 6.96-6.90 (m,1H), 6.53-6.47 (m, 1H), 5.91-5.81 (m, 1H), 4.62-4.40 (m, 2H), 3.48-3.38(m, 2H), 3.15-2.67 (m, 2H), 1.83-1.75 (m, 2H), 1.67-1.52 (m, 3H),1.44-1.28 (m, 4H), 1.25-1.13 (m, 2H); ¹³C NMR (100 MHz, CDCl₃): δ=159.3,157.5, 157.4, 150.5, 147.7, 145.1, 143.8, 116.9, 115.8, 115.6, 111.2,47.0, 42.5, 41.8, 36.0, 35.8, 32.7, 31.9, 29.5, 23.7; HRMS (ESI) forC₂₁H₂₆N₆O₂ [M+H]⁺ calcd: 395.2195, found: 395.2189.

(E)-2-Cyano-1-(pyridin-4-yl)-3-(4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)guanidine(FEI-159)

Obtained from amine 21c (40 mg, 0.15 mmol) and phenyl(Z)—N′-cyano-N-(pyridin-4-yl)carbamimidate (35.7 mg, 0.15 mmol)according to the same procedure as that used to prepare FEI-154. Yield:38.2 mg (62%, MW=410.54), white foam. ¹H NMR (400 MHz, CDCl₃):δ=8.40-8.28 (m, 2H), 7.38 (d, 1H, J=5.1 Hz), 7.21 (s, 1H), 7.18 (d, 2H,J=3.2 Hz), 6.97 (dd, 1H, J=4.8 Hz, 3.8 Hz), 4.41-4.20 (m, 2H), 3.34 (t,2H, J=7.1 Hz), 2.94-2.78 (m, 2H), 1.71-1.64 (m, 2H), 1.57-1.44 (m, 3H),1.34-1.19 (m, 4H), 1.10 (qd, 2H, J=12.3 Hz, 3.5 Hz); ¹³C NMR (100 MHz,CDCl₃): δ=163.7, 157.2, 149.9, 145.7, 137.0, 128.7, 128.5, 126.8, 116.9,115.3, 46.3, 42.5, 42.4, 36.0, 35.8, 32.7, 31.9, 29.4, 23.7; HRMS (ESI)for 021H₂₆N₆OS [M+H]⁺ calcd: 411.1967, found: 411.1962.

(E)-2-cyano-1-(4-(1-(4-(dimethoxymethyl)-2,6-dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridazin-4-yl)guanidine(FEI-162)

(4-(4-Aminobutyl)piperidin-1-yl)(4-dimethoxymethyl-2,6-dimethoxyphenyl)methanone(21e) was prepared from 4-(dimethoxymethyl)-2,6-dimethoxybenzoic acid(61.5 mg, 0.24 mmol) and piperidine salt 20 (81 mg, 0.25 mmol) accordingto the same procedure (2 steps) as that applied for the preparation of21a. The crude primary amine so-obtained was then mixed with phenyl(Z)—N′-cyano-N-(pyridazin-4-yl)carbamimidate (47.8 mg, 0.2 mmol) andEt₃N (34 □L. 0.24 mmol) in acetonitrile (2 mL). The mixture was stirredat 20° C. for 48 h (monitoring by TLC). The solvent was evaporated invacuo and the residue purified by FC (5/1 EtOAc/MeOH). Yield (3 steps):37.4 mg (27.7%, MW=539.637), white foam. ¹H NMR (400 MHz, CDCl₃):δ=8.89-8.68 (m, 2H), 7.91-7.71 (m, 1H), 7.0 (d, 1H, J=7.2 Hz), 6.58 (d,2H, J=8.1 Hz), 5.21 (s, 1H), 4.67 (d, 1H, J=12.0 Hz), 3.85-3.77 (m, 2H),3.71 (s, 3H), 3.70 (s, 3H), 3.40 (d, 1H, J=12.9 Hz), 3.26 (s, 6H), 2.92(t, 1H, J=12.8 Hz), 2.74 (t, 1H, J=12.2 Hz), 1.78 (d, 1H, J=11.0 Hz),1.61-1.41 (m, 4H), 1.40-1.04 (m, 6H); ¹³C NMR (100 MHz, CDCl₃): δ=165.9,156.9, 156.3, 141.8, 138.3, 119.8, 115.9, 114.6, 113.4, 105.3, 102.8,102.5, 56.2, 55.9, 53.2, 47.3, 42.7, 41.9, 35.9, 32.9, 31.7, 29.7, 23.6;HRMS (ESI) for C₂₇H₃₇N₇O₅ [M+H]⁺ calcd: 539.2856, found: 539.2854.

(E)-2-Cyano-1-(4-(1-(furan-2-carbonyl)piperidin-4-yl)butyl)-3-(pyridazin-4-yl)guanidine(FEI-164)

Obtained from amine 21b (37.5 mg, 0.15 mmol) and phenyl(Z)—N′-cyano-N-(pyridazin-4-yl)carbamimidate (35.9 mg, 0.15 mmol)according to the same procedure as that used to prepare FEI-162. Yield:33.7 mg (56.8%, MW=395.467), white foam. ¹H NMR (400 MHz, CDCl₃):δ=9.19-9.04 (m, 1H), 8.99-8.85 (m, 1H), 8.08-7.93 (m, 1H), 7.51-7.48 (m,1H), 6.92 (d, 1H, J=3.4 Hz), 6.50 (dd, 1H, J=3.3 Hz, 1.7 Hz), 4.60-4.37(m, 2H), 3.71-3.57 (m, 2H), 3.21-2.67 (m, 2H), 1.77 (d, 2H, J=12.2 Hz),1.73-1.65 (m, 2H), 1.62-1.50 (m, 1H), 1.46-1.38 (m, 2H), 1.36-1.29 (m,2H), 1.25-1.13 (m, 2H); ¹³C NMR (100 MHz, CDCl₃): δ=159.3, 150.8, 147.5,144.4, 143.9, 139.7, 129.7, 121.3, 115.8, 115.1, 111.3, 47.0, 43.6,42.8, 36.0, 35.9, 32.6, 31.9, 29.7, 23.6; HRMS (ESI) for C₂₀H₂₅N₇O₂[M+H]⁺ calcd: 396.2148, found: 396.2142.

(E)-1-(4-(1-Benzoylpiperidin-4-yl)butyl)-2-cyano-3-(6-fluoropyridin-3-yl)guanidine(FEI-166)

Obtained from amine 21a (40.0 mg, 0.15 mmol) and phenyl(Z)—N′-cyano-N-(6-fluoropyridin-3-yl)carbamimidate (38.4 mg, 0.15 mmol)according to the same procedure as that used to prepare FEI-162. Yield:36.3 mg (57.3%, MW=422.508), white foam. ¹H NMR (400 MHz, CDCl₃):δ=8.27-8.20 (m, 1H), 7.98 (s, 1H), 7.67 (t, 1H, J=6.5 Hz), 7.35-7.28 (m,3H), 7.27-7.22 (m, 2H), 6.83 (dd, 1H, J=8.5 Hz, 2.7 Hz), 5.55 (brs, 1H,N—H), 4.63-4.50 (m, 1H), 3.64 (d, 1H, J=10.8 Hz), 3.21 (q, 2H, J=6.1Hz), 2.89 (t, 1H, J=12.6 Hz), 2.66 (t, 1H, J=12.2 Hz), 1.77-1.68 (m,1H), 1.61-1.50 (m, 1H), 1.58-1.39 (m, 3H), 1.28-1.14 (m, 4H), 1.13-0.95(m, 2H); ¹³C NMR (100 MHz, CDCl₃): δ=170.4, 162.4 (J_(C-F)=239.8 Hz),158.7, 143.7, 138.4, 136.1, 131.2, 129.7, 128.5, 126.7, 117.7, 110.3(J_(C-F)=39.3 Hz), 48.1, 42.5, 42.2, 36.0, 35.9, 32.9, 31.8, 29.5, 23.7;HRMS (ESI) for C₂₃H₂₇FN₆O [M+H]⁺ calcd: 423.2309, found: 423.2296.

(E)-2-Cyano-1-(4-(1-(2,6-dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(6-fluoropyridin-3-yl)guanidine(FEI-167)

Obtained from amine 21d (48.0 mg, 0.15 mmol) and phenyl(Z)—N′-cyano-N-(6-fluoropyridin-3-yl)carbamimidate (38.4 mg, 0.15 mmol)according to the same procedure as that used to prepare FEI-162. Yield:38.5 mg (53.2%, MW=482.56), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.44(brs, 1H), 7.84 (s, 1H), 7.66 (td, 1H, J=6.5 Hz, 2.6 Hz), 7.16 (t, 1H,J=8.7 Hz), 6.74 (dd, 1H, J=8.6 Hz, 2.8 Hz), 6.43 (dd, 2H, J=11.2 Hz, 8.6Hz), 5.65 (brs, 1H, N—H), 4.65 (d, 1H, J=13.1 Hz), 3.70 (s, 3H), 3.65(s, 3H), 3.37 (d, 1H, J=13.1 Hz), 3.29 (q, 2H, J=6.2 Hz), 2.87 (t, 1H,J=11.2 Hz), 2.69 (t, 1H, J=12.4 Hz), 1.75 (d, 1H, J=12.4 Hz), 1.65-1.57(m, 1H), 1.53-1.40 (m, 4H), 1.34-1.17 (m, 3H), 1.06 (qd, 2H, J=12.0 Hz,3.5 Hz); ¹³C NMR (100 MHz, CDCl₃): δ=165.6, 161.8 (J_(C-F)=238.9 Hz),158.4, 156.4, 142.7, 137.1, 131.7, 130.6, 117.5, 113.9, 109.5(J_(C-F)=39.5 Hz), 103.9, 55.8, 47.1, 42.3, 41.8, 36.0, 35.9, 33.0,31.7, 29.7, 23.8; HRMS (ESI) for C₂₅H₃₁FN₆O₃ [M+H]⁺ calcd: 483.2520,found: 483.2515.

(E)-2-cyano-1-(4-(1-(4-(dimethoxymethyl)-2,6-dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(6-fluoropyridin-3-yl)guanidine(FEI-168)

Prepared from (4-(4-Aminobutyl)piperidin-1-yl)(4-dimethoxymethyl-2,6-dimethoxyphenyl)methanone (21e) and phenyl (Z)-phenylN′-cyano-N-(6-fluoropyridin-3-yl)carbamimidate (51.2 mg, 0.2 mmol)according to the same procedure as that used to prepare FEI-162. Yield(3 steps): 38.9 mg (34.9%, MW=556.639), white foam. ¹H NMR (400 MHz,CDCl₃): δ=8.39-8.29 (m, 1H), 7.89 (s, 1H), 7.68 (t, 1H, J=6.3 Hz), 6.76(dd, 1H, J=8.3 Hz, 2.3 Hz), 6.56 (d, 2H, J=11.2 Hz), 5.54 (brs, 1H),4.65 (d, 1H, J=12.7 Hz), 3.72 (s, 3H), 3.68 (s, 3H), 3.41-3.32 (m, 3H),3.28 (s, 6H), 2.86 (t, 1H, J=12.0 Hz), 2.68 (t, 1H, J=12.6 Hz), 1.74 (d,1H, J=12.6 Hz), 1.54-1.38 (m, 4H), 1.29-1.16 (m, 4H), 1.11-0.96 (m, 2H);¹³C NMR (100 MHz, CDCl₃): δ=165.4, 162.0, 159.6, 158.4, 156.4, 142.9,141.3, 137.3, 131.6, 114.0, 109.7, 102.0, 102.3, 55.9, 53.2, 47.0, 42.3,41.8, 36.1, 35.9, 34.1, 32.9, 31.7, 29.7, 23.8, 22.4; HRMS (ESI) forC₂₈H₃₇FN₆O₅ [M+H]⁺ calcd: 556.2809, found: 556.2813.

(E)-2-Cyano-1-(6-fluoropyridin-3-yl)-3-(4-(1-(furan-2-carbonyl)piperidin-4-yl)butyl)guanidine(FEI-170)

Obtained from amine 21b (37.5 mg, 0.15 mmol) and phenyl(Z)—N′-cyano-N-(6-fluoropyridin-3-yl)carbamimidate (38.4 mg, 0.15 mmol)according to the same procedure as that used to prepare FEI-162. Yield:33.5 mg (54.1%, MW=412.469), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.16(brs, 1H), 7.81 (t, 1H, J=6.5 Hz), 7.68-7.61 (m, 1H), 7.49 (s, 1H), 7.03(dd, 1H, J=8.6 Hz, 3.0 Hz), 6.93 (d, 1H, J=3.4 Hz), 6.49 (q, 1H, J=3.2Hz), 5.10 (brs, 1H, N—H), 4.62-4.41 (m, 2H), 3.34 (q, 2H, J=6.2 Hz),3.13-2.67 (m, 2H), 1.78 (d, 2H, J=12.7 Hz), 1.59-1.51 (m, 3H), 1.39-1.25(m, 4H), 1.21 (qd, 2H, J=12.4 Hz, 3.3 Hz); ¹³C NMR (100 MHz, CDCl₃):δ=159.2, 158.7, 147.8, 146.2, 144.2, 143.2, 142.6, 138.5, 131.0, 115.7,111.2, 110.5, 46.8, 42.4, 42.2, 36.0, 35.9, 32.7, 32.1, 29.5, 23.7; HRMS(ESI) for C₂₁H₂₅FN₆O₂ [M+H]⁺ calcd: 413.2101, found: 413.2094.

(E)-2-Cyano-1-(6-fluoropyridin-3-yl)-3-(4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)guanidine(FEI-171)

Obtained from amine 21c (40.0 mg, 0.15 mmol) and phenyl(Z)—N′-cyano-N-(6-fluoropyridin-3-yl)carbamimidate (38.4 mg, 0.15 mmol)according to the same procedure as that used to prepare FEI-162. Yield:36.9 mg (57.4%, MW=428.53), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.01(s, 1H), 7.75 (t, 1H, J=5.6 Hz), 7.37 (dd, 1H, J=5.0 Hz, 0.9 Hz), 7.19(dd, 1H, J=3.5 Hz, 0.8 Hz), 6.97 (dd, 1H, J=4.9 Hz, 3.7 Hz), 6.90 (dd,1H, J=8.7 Hz, 3.0 Hz), 4.42-4.16 (m, 2H), 3.23 (t, 2H, J=7.2 Hz),2.96-2.71 (m, 2H), 1.68 (d, 2H, J=12.0 Hz), 1.54-1.41 (m, 3H), 1.32-1.19(m, 4H), 1.11 (qd, 2H, J=12.3 Hz, 3.6 Hz); ¹³C NMR (100 MHz, CDCl₃):δ=163.7, 162.4 (J_(C-F)=240.0 Hz), 158.6, 158.4, 143.5, 138.4, 138.0,137.0, 128.6, 126.7, 117.6, 110.3 (J_(C-F)=40.0 Hz), 46.3, 42.2, 42.0,36.0, 35.9, 32.8, 31.7, 29.4, 23.7; HRMS (ESI) for C₂₁H₂₅FN₆OS [M+H]⁺calcd: 429.1873, found: 429.1872.

General Procedure for the Synthesis of FEI 186-188, FEI 190-201.

tert-Butyl 4-(3-oxopropyl)piperidine-1-carboxylate (23)

A solution of tert-butyl 4-(3-hydroxypropyl)piperidine-1-carboxylate(22, 1.00 g, 4.11 mmol) in CH₂Cl₂ (20 mL) was cooled to 0° C. Understirring 1,1,1-triacetoxy-1,1-dihydro-1,2-benziodoxol-3(1H)-one(Dess-Martin Reagent, 2.27 g, 5.34 mmol) was added portion-wise, thenthe mixture was stirred at 20° C. for 4 h. After filtration, thefiltrate was washed with a saturated aqueous solution of NaHCO₃ (20 mL),and then further washed with brine (20 mL) and dried (MgSO₄). Thesolvent was evaporated in vacuo, and the resulting residue was purifiedby FC (8/1 PE/EtOAc) to give 0.85 g (86%) of 23, colorless oil, that wasused directly in the next step.

tert-Butyl (E)-4-(5-ethoxy-5-oxopent-3-en-1-yl)piperidine-1-carboxylate(24)

Compound 24 was prepared from 23 (0.7 g, 2.9 mmol) and(carbethoxymethylene)triphenylphosphorane (1.21 g, 3.5 mmol) accordingto the same procedure as that used to prepare 11.

Yield: 0.83 g (92.2%), colorless oil. ¹H NMR (400 MHz, CDCl₃): δ=6.97(dt, 1H, J=15.7 Hz, 6.8 Hz), 5.84 (dt, 1H, J=15.6 Hz, 1.4 Hz), 4.21 (q,2H, J=7.3 Hz), 4.16-4.03 (m, 2H), 2.68 (t, 2H, J=10.9 Hz), 2.25 (q, 2H,J=6.8 Hz), 1.71-1.63 (m, 2H), 1.47 (s, 9H), 1.46-1.37 (m, 3H), 1.31 (t,3H, J=7.1 Hz), 1.11 (qd, 2H, J=10.7 Hz, 4.0 Hz).

tert-Butyl (E)-4-(5-hydroxypent-3-en-1-yl)piperidine-1-carboxylate (25)

Compound 25 was prepared from 24 (0.74 g, 2.38 mmol) according to thesame procedure as that used to prepare compound 12.

Yield: 0.56 g (87.5%), colorless oil. ¹H NMR (400 MHz, CDCl₃):δ=5.76-5.62 (m, 2H), 4.12 (t, 2H, J=5.3 Hz), 4.09-3.99 (m, 1H, O—H),2.69 (t, 2H, J=13.0 Hz), 2.10 (dd, 2H, J=14.1 Hz, 6.6 Hz), 1.75-1.62 (m,2H), 1.47 (s, 9H), 1.45-1.30 (m, 4H), 1.31-1.25 (m, 1H), 1.10 (qd, 2H,J=11.8 Hz, 3.9 Hz).

tert-Butyl 4-(5-ethoxy-5-oxopentyl)piperidine-1-carboxylate (26)

Compound 24 (0.6 g, 1.93 mmol) was dissolved in methanol (5 mL), thenPd/C (21.3 mg, 0.2 mol) was added. The reaction mixture stirred under H₂atmosphere at 20° C. overnight. The suspension was filtered on a Cellitebed and the cake was washed with MeOH (15 mL). After evaporation of thesolvent in vacuo, 0.54 g (89.4%) of 26 was obtained as yellow oil, whichwas used directly in the next step without further purification.

¹H NMR (400 MHz, CDCl₃): δ=4.15 (q, 2H, J=7.0 Hz), 4.12-4.02 (m, 2H),2.68 (t, 2H, J=12.5 Hz), 2.32 (t, 2H, J=7.6 Hz), 1.71-1.55 (m, 6H), 1.47(s, 9H), 1.42-1.32 (m, 3H), 1.27 (t, 3H, J=6.3 Hz), 1.08 (qd, 2H, J=11.9Hz, 4.1 Hz).

tert-Butyl 4-(5-hydroxypentyl)piperidine-1-carboxylate (27)

To a solution of compound 26 (0.54 g, 1.72 mmol) in THF (5 mL) was addedlithium aluminium hydride (0.2 g, 5.16 mmol) in small portions at 0° C.and under stirring. Then the mixture was stirred at 20° C. overnight(monitored by TLC). After the end of the reaction, the mixture wascooled to 0° C., and 30% aqueous KOH (5 mL) was added slowly undervigorous stirring. After further stirring at 20° C. for 1 h, thesuspension was filtered on a Cellite bed and the cake was washed withTHF (15 mL). Evaporation of the solvent in vacuo; the crude was purifiedby FC (3/1 PE/EtOAc) to give 0.37 g (78.7%) of 27 as yellow oil.

¹H NMR (400 MHz, CDCl₃): δ=4.18-3.95 (m, 2H), 2.81-2.59 (m, 4H),1.70-1.62 (m, 2H), 1.47 (s, 9H), 1.38-1.29 (m, 6H), 1.30-1.21 (m, 3H),1.08 (qd, 2H, J=12.1 Hz, 4.0 Hz).

Compound 28a-d were prepared from 27 (0.27 g, 1.0 mmol) following thesame procedure as that used to prepare 21a-d. The crude 21a-d were useddirectly in the next step. Yield: 45˜55% (4 steps).

(E)-1-(5-(1-Benzoylpiperidin-4-yl)pentyl)-2-cyano-3-(pyridin-3-yl)guanidine(FEI-186)

Obtained from amine 28a (41.2 mg, 0.15 mmol) and phenyl(Z)—N′-cyano-N-(pyridin-3-yl)carbamimidate (35.7 mg, 0.15 mmol)according to the same procedure as that used to prepare FEI-154. Yield:34.2 mg (54.5%, MW=405.2052), white foam. ¹H NMR (400 MHz, CDCl₃):δ=8.64-8.42 (m, 2H), 8.11-8.01 (m, 1H), 7.69 (d, 1H, J=7.7 Hz),7.44-7.34 (m, 5H), 5.33 (brs, 1H, N—H), 4.69 (d, 1H, J=11.8 Hz), 3.74(d, 1H, J=11.4 Hz), 3.31 (q, 2H, J=6.4 Hz), 2.98 (t, 1H, J=12.4 Hz),2.76 (t, 1H, J=12.8 Hz), 1.85-1.71 (m, 2H), 1.67-1.46 (m, 4H), 1.37-1.24(m, 5H), 1.20-1.05 (m, 2H); ¹³C NMR (100 MHz, CDCl₃): δ=170.3, 158.5,147.1, 145.8, 136.2, 133.4, 132.2, 129.6, 128.5, 126.7, 124.0, 117.6,48.2, 42.6, 42.3, 36.2, 36.0, 33.0, 32.0, 29.3, 26.8, 26.2; HRMS (ESI)for C₂₄H₃₀N₆O [M+H]⁺ calcd: 419.2559, found: 419.2554.

(E)-2-Cyano-1-(5-(1-(furan-2-carbonyl)piperidin-4-yl)pentyl)-3-(pyridin-3-yl)guanidine(FEI-187)

Obtained from amine 28b (39.6 mg, 0.15 mmol) and phenyl(Z)—N′-cyano-N-(pyridin-3-yl)carbamimidate (35.7 mg, 0.15 mmol)according to the same procedure as that used to prepare FEI-154. Yield:32.6 mg (53.2%), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.66-8.40 (m,2H), 8.22-8.09 (m, 1H), 7.71 (d, 1H, J=7.2 Hz), 7.49-7.47 (m, 1H), 7.37(brs, 1H, N—H), 6.94-6.90 (m, 1H), 6.49-6.46 (m, 1H), 5.42 (brs, 1H,N—H), 4.61-4.36 (m, 2H), 3.33 (q, 2H, J=6.5 Hz), 3.15-2.68 (m, 2H),1.82-1.72 (m, 2H), 1.62-1.50 (m, 3H), 1.37-1.25 (m, 6H), 1.23-1.13 (m,2H); ¹³C NMR (100 MHz, CDCl₃): δ=159.2, 158.5, 147.9, 147.2, 145.8,143.6, 133.4, 132.2, 124.2, 117.7, 115.6, 111.2, 47.0, 43.4, 42.2, 36.2,36.0, 33.0, 32.1, 29.3, 26.9, 26.2; HRMS (ESI) for C₂₂H₂₈N₆O₂ [M+H]⁺calcd: 409.2352, found: 409.2348.

(E)-2-Cyano-1-(pyridin-3-yl)-3-(5-(1-(thiophene-2-carbonyl)piperidin-4-yl)pentyl)guanidine(FEI-188)

Obtained from amine 28c (42.2 mg, 0.15 mmol) and phenyl(Z)—N′-cyano-N-(pyridin-3-yl)carbamimidate (35.7 mg, 0.15 mmol)according to the same procedure as that used to prepare FEI-154. Yield:33.5 mg (52.6%), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.65-8.39 (m,2H), 8.14-8.01 (m, 1H), 7.70 (d, 1H, J=6.6 Hz), 7.44 (d, 1H, J=4.9 Hz),7.37 (brs, 1H, N—H), 7.27 (d, 1H, J=3.3 Hz), 7.05 (t, 1H, J=4.0 Hz),5.37 (brs, 1H, N—H), 4.54-4.27 (m, 2H), 3.33 (q, 2H, J=6.2 Hz),3.03-2.82 (m, 2H), 1.82-1.71 (m, 2H), 1.60-1.50 (m, 3H), 1.37-1.24 (m,6H), 1.19 (qd, 2H, J=12.3 Hz, 3.4 Hz); ¹³C NMR (100 MHz, CDCl₃):δ=163.5, 158.5, 147.1, 145.8, 137.3, 133.4, 132.2, 128.5, 128.3, 126.7,124.2, 117.7, 47.1, 44.6, 42.2, 36.2, 36.0, 33.0, 32.1, 29.3, 26.9,26.2; HRMS (ESI) for C₂₂H₂₈N₆OS [M+H]⁺ calcd: 425.2123, found: 425.2126.

(E)-1-(5-(1-Benzoylpiperidin-4-yl)pentyl)-2-cyano-3-(pyridin-4-yl)guanidine(FEI-190)

Obtained from amine 28a (41.2 mg, 0.15 mmol) and phenyl(Z)—N′-cyano-N-(pyridin-4-yl)carbamimidate (35.7 mg, 0.15 mmol)according to the same procedure as that used to prepare FEI-154. Yield:35.4 mg (56.4%), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.42-8.21 (m,2H), 7.37-7.30 (m, 3H), 7.29-7.26 (m, 2H), 7.16-7.04 (m, 2H), 5.97 (m,1H, N—H), 4.58 (d, 1H, J=12.4 Hz), 3.66 (d, 1H, J=12.4 Hz), 3.31 (q, 2H,J=6.4 Hz), 2.92 (t, 1H, J=12.8 Hz), 2.68 (t, 1H, J=12.6 Hz), 1.78-1.69(m, 1H), 1.58-1.42 (m, 4H), 1.28-1.17 (m, 6H), 1.14-0.98 (m, 2H); ¹³CNMR (100 MHz, CDCl₃): δ=170.5, 157.4, 150.6, 144.9, 136.1, 129.7, 128.6,126.7, 116.8, 115.5, 48.2, 42.7, 42.5, 36.2, 36.0, 33.0, 32.0, 29.3,26.9, 26.2; HRMS (ESI) for C₂₄H₃₀N₆O [M+H]⁺ calcd: 419.2559, found:419.2556.

(E)-2-Cyano-1-(5-(1-(furan-2-carbonyl)piperidin-4-yl)pentyl)-3-(pyridin-4-yl)guanidine(FEI-191)

Obtained from amine 28b (39.6 mg, 0.15 mmol) and phenyl(Z)—N′-cyano-N-(pyridin-4-yl)carbamimidate (35.7 mg, 0.15 mmol)according to the same procedure as that used to prepare FEI-154. Yield:34.5 mg (56.3%), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.47-8.23 (m,2H), 7.42-7.37 (m, 1H), 7.22-7.12 (m, 2H), 6.81 (d, 1H, J=3.4 Hz), 6.40(q, 1H, J=1.8 Hz), 6.10-6.05 (m, 1H, N—H), 4.52-4.27 (m, 2H), 3.34 (q,2H, J=6.7 Hz), 3.12-2.54 (m, 2H), 1.74-1.65 (m, 2H), 1.56-1.42 (m, 3H),1.30-1.16 (m, 6H), 1.09 (qd, 2H, J=12.8 Hz, 2.4 Hz); ¹³C NMR (100 MHz,CDCl₃): δ=159.3, 157.5, 150.5, 147.7, 145.2, 143.8, 117.0, 115.7, 115.6,111.3, 47.2, 43.4, 42.6, 36.2, 36.0, 32.8, 32.3, 29.3, 26.9, 26.2; HRMS(ESI) for C₂₂H₂₈N₆O₂ [M+H]⁺ calcd: 409.2352, found: 409.2348.

(E)-2-Cyano-1-(pyridin-4-yl)-3-(5-(1-(thiophene-2-carbonyl)piperidin-4-yl)pentyl)guanidine(FEI-192)

Obtained from amine 28c (42.2 mg, 0.15 mmol) and phenyl(Z)—N′-cyano-N-(pyridin-4-yl)carbamimidate (35.7 mg, 0.15 mmol)according to the same procedure as that used to prepare FEI-150. Yield:35.8 mg (56.3%), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.60-8.31 (m,2H), 7.44 (dd, 1H, J=11.5 Hz, 5.2 Hz), 7.30-7.18 (m, 3H), 7.07-7.01 (m,1H), 6.09-5.99 (m, 1H, N—H), 4.50-4.27 (m, 2H), 3.39 (q, 2H, J=5.8 Hz),3.02-2.82 (m, 2H), 1.80-1.70 (m, 2H), 1.64-1.49 (m, 3H), 1.38-1.24 (m,6H), 1.16 (qd, 2H, J=11.8 Hz, 3.5 Hz); ¹³C NMR (100 MHz, CDCl₃):δ=163.5, 157.5, 150.6, 145.0, 137.1, 128.6, 128.4, 126.8, 116.8, 115.6,47.7, 42.7, 42.5, 36.2, 36.0, 32.7, 32.3, 29.2, 26.8, 26.2; HRMS (ESI)for C₂₂H₂₈N₆OS [M+H]⁺ calcd: 425.2123, found: 425.2127.

(E)-2-Cyano-1-(5-(1-(2,6-dimethoxybenzoyl)piperidin-4-yl)pentyl)-3-(pyridin-4-yl)guanidine(FEI-193)

Obtained from amine 28d (50.1 mg, 0.15 mmol) and phenyl(Z)—N′-cyano-N-(pyridin-4-yl)carbamimidate (35.7 mg, 0.15 mmol)according to the same procedure as that used to prepare FEI-154. Yield:38.7 mg (54%), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.41-8.05 (m, 2H),7.22-7.18 (m, 1H), 7.12-6.94 (m, 2H), 6.46 (d, 2H, J=8.3 Hz), 6.18 (brs,1H, N—H), 4.65 (d, 1H, J=13.2 Hz), 3.69 (s, 3H), 3.67 (s, 3H), 3.48-3.35(m, 3H), 2.91 (t, 1H, J=12.8 Hz), 2.72 (t, 1H, J=12.5 Hz), 1.81-1.71 (m,1H), 1.57-1.38 (m, 4H), 1.33-1.18 (m, 6H), 1.14-1.02 (m, 2H); ¹³C NMR(100 MHz, CDCl₃): δ=165.8, 157.0, 156.3, 150.0, 145.4, 130.8, 116.8,114.7, 113.8, 104.0, 55.8, 47.2, 42.7, 42.0, 36.4, 36.2, 33.0, 32.0,29.6, 27.0, 26.5; HRMS (ESI) for C₂₆H₃₄N₆O₃ [M+H]⁺ calcd: 479.2771,found: 479.2768.

Compound 29a-d were prepared from 25 (0.53 g, 1.97 mmol) following thesame procedure as that used to prepare 21, and used directly in the nextstep. Yield: 4555% (4 steps).

(E)-1-((E)-5-(1-Benzoylpiperidin-4-yl)pent-2-en-1-yl)-2-cyano-3-(pyridin-3-yl)guanidine(FEI-194)

Obtained from amine 29a (54.4 mg, 0.2 mmol) and phenyl(Z)—N′-cyano-N-(pyridin-3-yl)carbamimidate (47.6 mg, 0.2 mmol) accordingto the same procedure as that used to prepare FEI-154. Yield: 42.5 mg(51%, MW=416.2325), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.53-8.45 (m,2H), 8.41-8.37 (m, 1H, N—H), 7.72 (d, 1H, J=7.8 Hz), 7.43-7.34 (m, 6H),5.92-5.76 (m, 1H, N—H), 5.66 (dt, 1H, J=15.3 Hz, 6.2 Hz), 5.46 (dt, 1H,J=15.3 Hz, 6.0 Hz), 4.67 (d, 1H, J=11.2 Hz), 3.89 (t, 2H, J=5.5 Hz),3.73 (d, 1H, J=11.6 Hz). 2.98 (t, 1H, J=12.8 Hz), 2.75 (t, 1H, J=12.9Hz), 1.86-1.74 (m, 1H), 1.68-1.59 (m, 1H), 1.58-1.48 (m, 2H), 1.40-1.32(m, 3H), 1.24-1.07 (m, 2H); ¹³C NMR (100 MHz, CDCl₃): δ=170.3, 158.5,147.0, 145.5, 136.2, 124.6, 133.4, 131.9, 129.6, 128.5, 126.7, 124.8,124.1, 117.6, 48.1, 44.1, 42.5, 35.6 (2C), 32.8, 31.8, 29.2; HRMS (ESI)for C₂₄H₂₈N₆O [M+H]⁺ calcd: 417.2403, found: 417.2401.

(E)-2-Cyano-1-((E)-5-(1-(furan-2-carbonyl)piperidin-4-yl)pent-2-en-1-yl)-3-(pyridin-3-yl)guanidine(FEI-195)

Obtained from amine 29b (52.4 mg, 0.2 mmol) and phenyl(Z)—N′-cyano-N-(pyridin-3-yl)carbamimidate (47.6 mg, 0.2 mmol) accordingto the same procedure as that used to prepare FEI-154. Yield: 43.4 mg(53.4%, MW=406.2117), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.58-8.31(m, 2H), 8.27-8.09 (m, 1H, N—H), 7.65 (d, 1H, J=8.1 Hz), 7.41-7.38 (m,1H), 7.28-7.22 (m, 1H), 6.83 (d, 1H, J=3.5 Hz), 6.39 (dd, 1H, J=3.5 Hz,1.8 Hz), 5.81-5.67 (m, 1H, N—H), 5.59 (dt, 1H, J=15.3 Hz, 6.4 Hz), 5.40(dt, 1H, J=15.4 Hz, 6.0 Hz), 4.49-4.29 (m, 2H), 3.83 (t, 2H, J=5.6 Hz),3.10-2.56 (m, 2H), 1.73-1.64 (m, 2H), 1.52-1.41 (m, 2H), 1.31-1.22 (m,3H), 1.11 (qd, 2H, J=12.0 Hz, 3.7 Hz); ¹³C NMR (100 MHz, CDCl₃):δ=159.2, 158.5, 147.9, 147.2, 145.7, 143.6, 134.7, 133.4, 132.1, 124.8,124.1, 117.5, 115.7, 111.2, 46.8, 44.1, 42.3, 35.6, 35.4, 32.7, 32.0,29.2; HRMS (ESI) for C₂₂H₂₆N₆O₂ [M+H]⁺ calcd: 407.2195, found: 407.2193.

(E)-2-Cyano-1-(pyridin-3-yl)-3-((E)-5-(1-(thiophene-2-carbonyl)piperidin-4-yl)pent-2-en-1-yl)guanidine(FEI-196)

Obtained from amine 29c (55.6 mg, 0.2 mmol) and phenyl(Z)—N′-cyano-N-(pyridin-3-yl)carbamimidate (47.6 mg, 0.2 mmol) accordingto the same procedure as that used to prepare FEI-154. Yield: 43.7 mg(51.8%, MW=422.1889), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.49-8.30(m, 2H), 8.20-8.00 (m, 1H, N—H), 7.64 (d, 1H, J=7.8 Hz), 7.35 (dd, 1H,J=5.0 Hz, 0.9 Hz), 7.28-7.22 (m, 1H), 7.17 (dd, 1H, J=3.6 Hz, 1.0 Hz),6.96 (dd, 1H, J=5.0 Hz, 3.6 Hz), 5.77-5.62 (m, 1H, N—H), 5.60 (dt, 1H,J=15.4 Hz, 6.3 Hz), 5.40 (dt, 1H, J=15.4 Hz, 5.8 Hz), 4.43-4.20 (m, 2H),3.82 (t, 2H, J=5.6 Hz), 2.93-2.73 (m, 2H), 1.72-1.63 (m, 2H), 1.53-1.42(m, 2H), 1.32-1.24 (m, 3H), 1.11 (qd, 2H, J=12.2 Hz, 3.9 Hz); ¹³C NMR(100 MHz, CDCl₃): δ=163.5, 158.5, 147.3, 145.6, 137.3, 134.7, 133.3,132.1, 128.5, 128.3, 126.7, 124.8, 124.1, 117.5, 46.6, 44.8, 44.1, 35.6,35.5, 32.5, 32.2, 29.2; HRMS (ESI) for C₂₂H₂₆N₆OS [M+H]⁺ calcd:423.1967, found: 423.1972.

(E)-2-Cyano-1-((E)-5-(1-(2,6-dimethoxybenzoyl)piperidin-4-yl)pent-2-en-1-yl)-3-(pyridin-3-yl)guanidine(FEI-197)

Obtained from amine 29d (66.4 mg, 0.2 mmol) and phenyl(Z)—N′-cyano-N-(pyridin-3-yl)carbamimidate (47.6 mg, 0.2 mmol) accordingto the same procedure as that used to prepare FEI-154. Yield: 44.6 mg(46.8%, MW=476.2536), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.37-8.25(m, 2H), 8.20-8.13 (m, 1H, N—H), 7.64 (d, 1H, J=8.4 Hz), 7.19-7.13 (m,1H), 7.17 (t, 1H, J=8.8 Hz), 6.46 (dd, 2H, J=8.4 Hz, 3.4 Hz), 5.69-5.63(m, 1H, N—H), 5.61 (dt, 1H, J=15.4 Hz, 7.0 Hz), 5.39 (dt, 1H, J=15.4 Hz,6.0 Hz), 4.66 (d, 1H, J=12.7 Hz), 3.85 (t, 2H, J=5.4 Hz), 3.70 (s, 3H),3.68 (s, 3H), 3.38 (d, 1H, J=13.3 Hz), 2.86 (t, 1H, J=13.3 Hz), 2.67 (t,1H, J=12.7 Hz), 1.74-1.66 (m, 1H), 1.54-1.48 (m, 1H), 1.45-1.36 (m, 2H),1.31-1.22 (m, 3H), 1.06 (qd, 2H, J=11.8 Hz, 4.1 Hz); ¹³C NMR (100 MHz,CDCl₃): δ=165.5, 158.1, 156.5, 146.5, 144.7, 134.8, 133.5, 130.9, 130.3,124.6, 123.8, 117.2, 114.4, 104.0, 55.9, 47.0, 44.2, 41.8, 35.7, 35.6,32.7, 31.8, 29.3; HRMS (ESI) for C₂₆H₃₂N₆O₃ [M+H]⁺ calcd: 477.2614,found: 477.2608.

(E)-1-((E)-5-(1-Benzoylpiperidin-4-yl)pent-2-en-1-yl)-2-cyano-3-(pyridin-4-yl)guanidine(FEI-198)

Obtained from amine 29a (54.4 mg, 0.2 mmol) and phenyl(Z)—N′-cyano-N-(pyridin-4-yl)carbamimidate (47.6 mg, 0.2 mmol) accordingto the same procedure as that used to prepare FEI-154. Yield: 43.2 mg(52%, MW=416.2325), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.50-8.21 (m,2H), 7.35-7.31 (m, 3H), 7.29-7.26 (m, 2H), 7.16-7.04 (m, 2H), 6.14 (brs,1H, N—H), 5.65 (dt, 1H, J=15.4 Hz, 6.6 Hz), 5.41 (dt, 1H, J=15.4 Hz, 6.1Hz), 4.65-4.50 (m, 1H), 3.87 (t, 2H, J=5.4 Hz), 3.72-3.59 (m, 1H), 2.91(t, 1H, J=12.8 Hz), 2.67 (t, 1H, J=12.9 Hz), 1.78-1.54 (m, 2H),1.52-1.43 (m, 2H), 1.32-1.25 (m, 3H), 1.15-0.98 (m, 2H); ¹³C NMR (100MHz, CDCl₃): δ=170.5, 157.6, 150.6, 144.8, 136.1, 135.2, 129.7, 128.6,126.7, 124.5, 116.7, 115.4, 48.1, 44.4, 42.5, 35.7, 35.6, 32.8, 31.8,29.3; HRMS (ESI) for C₂₄H₂₈N₆O [M+H]⁺ calcd: 417.2403, found: 417.2404.

(E)-2-Cyano-1-((E)-5-(1-(furan-2-carbonyl)piperidin-4-yl)pent-2-en-1-yl)-3-(pyridin-4-yl)guanidine(FEI-199)

Obtained from amine 29b (52.4 mg, 0.2 mmol) and phenyl(Z)—N′-cyano-N-(pyridin-4-yl)carbamimidate (47.6 mg, 0.2 mmol) accordingto the same procedure as that used to prepare FEI-154. Yield: 45.7 mg(56.3%, MW=406.2117), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.48-8.30(m, 2H), 7.43-7.38 (m, 1H), 7.19-7.10 (m, 2H), 6.83 (d, 1H, J=3.5 Hz),6.40 (dd, 1H, J=3.3 Hz, 1.7 Hz), 6.09 (brs, 1H, N—H), 5.67 (dt, 1H,J=15.5 Hz, 6.4 Hz), 5.44 (dt, 1H, J=15.5 Hz, 6.0 Hz), 4.50-4.28 (m, 2H),3.90 (t, 2H, J=5.6 Hz), 3.16-2.48 (m, 2H), 1.75-1.65 (m, 2H), 1.58-1.43(m, 2H), 1.34-1.25 (m, 3H), 1.13 (qd, 2H, J=12.2 Hz, 3.0 Hz); ¹³C NMR(100 MHz, CDCl₃): δ=159.3, 157.7, 150.8, 147.8, 144.7, 143.7, 135.3,124.5, 116.8, 115.8, 115.5, 111.2, 46.9, 44.4, 43.3, 35.6, 35.5, 32.8,31.8, 29.3; HRMS (ESI) for C₂₂H₂₆N₆O₂ [M+H]⁺ calcd: 407.2195, found:407.2195.

(E)-2-Cyano-1-(pyridin-4-yl)-3-((E)-5-(1-(thiophene-2-carbonyl)piperidin-4-yl)pent-2-en-1-yl)guanidine(FEI-200)

Obtained from amine 29c (55.6 mg, 0.2 mmol) and phenyl(Z)—N′-cyano-N-(pyridin-4-yl)carbamimidate (47.6 mg, 0.2 mmol) accordingto the same procedure as that used to prepare FEI-154. Yield: 44.5 mg(52.7%, MW=422.1889), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.47-8.28(m, 2H), 7.36 (dd, 1H, J=5.1 Hz, 0.9 Hz), 7.18 (dd, 1H, J=3.5 Hz, 0.9Hz), 7.17-7.08 (m, 2H), 6.97 (dd, 1H, J=4.8 Hz, 3.7 Hz), 6.18 (brs, 1H,N—H), 5.67 (dt, 1H, J=15.2 Hz, 6.4 Hz), 5.43 (dt, 1H, J=15.4 Hz, 5.8Hz), 4.44-4.16 (m, 2H), 3.89 (t, 2H, J=5.4 Hz), 2.96-2.70 (m, 2H),1.72-1.63 (m, 2H), 1.56-1.40 (m, 2H), 1.34-1.23 (m, 3H), 1.11 (qd, 2H,J=12.3 Hz, 3.6 Hz); ¹³C NMR (100 MHz, CDCl₃): δ=163.6, 157.7, 150.7,144.8, 137.1, 135.1, 128.6, 128.5, 126.8, 124.6, 116.9, 115.5, 47.1,44.4, 43.9, 35.6, 35.5, 32.8, 31.8, 29.3; HRMS (ESI) for C₂₂H₂₆N₆OS[M+H]⁺ calcd: 423.1967, found: 423.1964.

(E)-2-Cyano-1-((E)-5-(1-(2,6-dimethoxybenzoyl)piperidin-4-yl)pent-2-en-1-yl)-3-(pyridin-4-yl)guanidine(FEI-201)

Obtained from amine 29d (66.4 mg, 0.2 mmol) and phenyl(Z)—N′-cyano-N-(pyridin-4-yl)carbamimidate (47.6 mg, 0.2 mmol) accordingto the same procedure as that used to prepare FEI-154. Yield: 46.4 mg(48.7%, MW=476.2536), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.35-8.13(m, 2H), 7.19 (t, 1H, J=8.6 Hz), 7.11-6.96 (m, 2H), 6.46 (d, 2H, J=8.4Hz), 6.13 (brs, 1H, N—H), 5.68 (dt, 1H, J=15.4 Hz, 6.4 Hz), 5.44 (dt,1H, J=15.3 Hz, 6.0 Hz), 4.65 (d, 1H, J=12.6 Hz), 3.99 (t, 2H, J=5.6 Hz),3.68 (s, 3H), 3.67 (s, 3H), 3.41 (d, 1H, J=13.2 Hz), 2.90 (t, 1H, J=12.1Hz), 2.71 (t, 1H, J=12.2 Hz), 1.80-1.69 (m, 1H), 1.58-1.50 (m, 1H),1.50-1.37 (m, 2H), 1.35-1.25 (m, 3H), 1.09 (m, 2H); ¹³C NMR (100 MHz,CDCl₃): δ=156.8, 157.0, 156.4, 150.2, 145.2, 135.0, 130.7, 124.5, 116.7,114.7, 113.8, 103.8, 55.9, 47.1, 44.6, 41.9, 35.6, 35.5, 32.8, 31.9,29.4; HRMS (ESI) for C₂₆H₃₂N₆O₃ [M+H]⁺ calcd: 477.2614, found: 477.2608.

General Procedure for the Synthesis of FEI 202-209.

1-(4-(1-Benzoylpiperidin-4-yl)butyl)-3-(pyridin-3-yl)urea (FEI-202)

Obtained from amine 21a (39.0 mg, 0.15 mmol) and phenylpyridin-3-ylcarbamate (32.2 mg, 0.15 mmol) according to the sameprocedure as that used to prepare FEI-154. Yield: 37.8 mg (66.3%,MW=380.2212), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.27-8.18 (m, 2H),8.17 (s, 1H), 8.0 (d, 1H, J=8.4 Hz), 7.48-7.36 (m, 5H), 7.18 (brs, 1H,N—H), 5.87 (t, 1H, J=5.2 Hz, N—H), 4.69 (d, 1H, J=11.6 Hz), 3.75 (d, 1H,J=12.0 Hz), 3.19 (q, 2H, J=6.1 Hz), 3.0 (t, 1H, J=12.1 Hz), 2.78 (t, 1H,J=11.6 Hz), 1.88-1.75 (m, 1H), 1.68-1.57 (m, 1H), 1.56-1.39 (m, 3H),1.36-1.23 (m, 4H), 1.22-1.05 (m, 2H); ¹³C NMR (100 MHz, CDCl₃): δ=170.6,156.1, 142.7, 139.9, 137.0, 135.9, 129.9, 128.7, 126.6, 125.7, 123.7,48.3, 42.7, 39.8, 36.0 (2C), 33.0, 31.8, 30.2, 23.9; HRMS (ESI) forC₂₂H₂₈N₄O₂ [M+H]⁺ calcd: 381.2291, found: 381.2295.

1-(4-(1-(Furan-2-carbonyl)piperidin-4-yl)butyl)-3-(pyridin-3-Aurea(FEI-203)

Obtained from amine 21b (37.5 mg, 0.15 mmol) and phenylpyridin-3-ylcarbamate (32.2 mg, 0.15 mmol) according to the sameprocedure as that used to prepare FEI-154. Yield: 47.0 mg (84.6%,MW=370.2005), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.34 (brs, 1H),8.21 (brs, 1H), 8.10 (d, 1H, J=8.1 Hz), 8.04 (s, 1H), 7.51 (d, 1H, J=0.7Hz), 7.22 (brs, 1H, N—H), 6.94 (d, 1H, J=3.4 Hz), 6.50 (dd, 1H, J=3.2Hz, 1.7 Hz), 5.84 (t, 1H, J=5.1 Hz, N—H), 4.70-4.34 (m, 2H), 3.27 (q,2H, J=5.8 Hz), 3.20-2.97 (m, 1H), 2.94-2.65 (m, 1H), 1.82-1.70 (m, 2H),1.61-1.46 (m, 3H), 1.40-1.25 (m, 4H), 1.25-1.12 (m, 2H); ¹³C NMR (100MHz, CDCl₃): δ=159.5, 156.1, 147.5, 144.0, 142.8, 140.0, 137.1, 125.8,123.8, 115.9, 111.3, 47.2, 43.6, 39.9, 36.1, 36.0, 32.9, 31.9, 30.2,23.8; HRMS (ESI) for C₂₀H₂₆N₄O₃ [M+H]⁺ calcd: 371.2083, found: 371.2085.

1-(Pyridin-3-yl)-3-(4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)urea(FEI-204)

Obtained from amine 21c (40.0 mg, 0.15 mmol) and phenylpyridin-3-ylcarbamate (32.2 mg, 0.15 mmol) according to the sameprocedure as that used to prepare FEI-154. Yield: 46.0 mg (87.9%,MW=386.1776), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.28 (brs, 1H),8.19 (brs, 1H), 8.07 (d, 1H, J=8.2 Hz), 8.0 (s, 1H), 7.47 (d, 1H, J=4.4Hz), 7.30 (d, 1H, J=3.3 Hz), 7.24-7.17 (m, 1H, N—H), 7.07 (dd, 1H, J=4.7Hz, 4.1 Hz), 5.81 (brs, 1H, N—H), 4.66-4.15 (m, 2H), 3.25 (q, 2H, J=5.7Hz), 3.13-2.76 (m, 2H), 1.83-1.69 (m, 2H), 1.59-1.41 (m, 3H), 1.40-1.25(m, 4H), 1.19 (q, 2H, J=12.2 Hz, 3.3 Hz); ¹³C NMR (100 MHz, CDCl₃):δ=163.8, 156.1, 142.8, 140.0, 137.0, 128.7, 128.6, 126.9, 126.0, 125.8,123.8, 47.5, 44.0, 39.8, 36.1, 36.0, 32.6, 31.9, 30.2, 23.8; HRMS (ESI)for C₂₀H₂₆N₄O₂S [M+H]⁺ calcd: 387.1855, found: 387.1857.

1-(4-(1-(2,6-Dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)urea(FEI-205)

Obtained from amine 21d (48.0 mg, 0.15 mmol) and phenylpyridin-3-ylcarbamate (32.2 mg, 0.15 mmol), according to the sameprocedure as that used to prepare FEI-154. Yield: 31.3 mg (47.4%,MW=440.2424), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.29 (d, 1H, J=5.3Hz), 8.23-8.04 (m, 2H), 8.0 (d, 1H, J=8.3 Hz), 7.27 (t, 1H, J=8.3 Hz),7.14 (brs, 1H, N—H), 6.56 (dd, 2H, J=8.3 Hz, 5.4 Hz), 6.01 (t, 1H, J=5.4Hz, N—H), 4.78 (d, 1H, J=13.0 Hz), 3.78 (s, 3H), 3.76 (s, 3H), 3.49 (d,1H, J=13.3 Hz), 3.19 (q, 2H, J=5.8 Hz), 2.98 (t, 1H, J=12.8 Hz), 2.80(td, 1H, J=12.5 Hz, 2.3 Hz), 1.88-1.78 (m, 1H), 1.63-1.55 (m, 1H),1.50-1.42 (m, 3H), 1.36-1.25 (m, 4H), 1.22-1.08 (m, 2H); ¹³C NMR (100MHz, CDCl₃): δ=165.9, 156.5, 156.2, 142.3, 139.9, 137.2, 130.7, 125.3,123.5, 114.0, 103.9, 55.9, 47.3, 42.0, 39.7, 36.1, 36.0, 33.0, 31.7,30.2, 23.9; HRMS (ESI) for C₂₄H₃₂N₄O₄ [M+H]⁺ calcd: 441.2502, found:441.2496.

1-(4-(1-Benzoylpiperidin-4-yl)butyl)-3-(pyridin-4-yl)urea (FEI-206)

Obtained from amine 21a (39.0 mg, 0.15 mmol) and phenylpyridin-4-ylcarbamate (32.2 mg, 0.15 mmol) according to the sameprocedure as that used to prepare FEI-154. Yield: 48.2 mg (84.5%.MW=380.2212), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.64 (brs, 1H,N—H), 8.38-8.03 (m, 2H), 7.40-7.32 (m, 3H), 7.31-7.28 (m, 2H), 7.19-7.05(m, 2H), 5.92 (t, 1H, J=5.4 Hz, N—H), 4.60 (d, 1H, J=11.4 Hz), 3.67 (d,1H, J=12.1 Hz), 2.80 (q, 2H, J=6.2 Hz), 2.93 (t, 1H, J=12.3 Hz), 2.70(t, 1H, J=11.8 Hz), 1.73 (d, 1H, J=11.2 Hz), 1.55 (d, 1H, J=11.2 Hz),1.48-1.30 (m, 3H), 1.27-1.14 (m, 4H), 1.12-0.95 (m, 2H); ¹³C NMR (100MHz, CDCl₃): δ=170.1, 155.4, 149.8, 147.6, 135.9, 130.9, 128.7, 126.6,112.5, 48.3, 42.8, 39.7, 36.0, 35.9, 33.0, 31.8, 30.2, 23.8; HRMS (ESI)for C₂₂H₂₈N₄O₂ [M+H]⁺ calcd: 381.2291, found: 381.2295.

1-(4-(1-(Furan-2-carbonyl)piperidin-4-yl)butyl)-3-(pyridin-4-Aurea(FEI-207)

Obtained from amine 21b (37.5 mg, 0.15 mmol) and phenylpyridin-4-ylcarbamate (32.2 mg, 0.15 mmol) according to the sameprocedure as that used to prepare FEI-154. Yield: 50.8 mg (91.5%,MW=370.2005), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.64 (brs, 1H,N—H), 8.25 (brs, 2H), 7.42 (dd, 1H, J=1.7 Hz, 0.7 Hz), 7.27 (brs, 2H),6.85 (dd, 1H, J=3.5 Hz, 0.7 Hz), 6.42 (dd, 1H, J=3.4 Hz, 1.7 Hz), 5.96(t, 1H, J=5.5 Hz, N—H), 4.54-4.26 (m, 2H), 3.17 (q, 2H, J=6.0 Hz),3.10-2.90 (m, 1H), 2.83-2.61 (m, 1H), 1.72-1.63 (m, 2H), 1.50-1.36 (m,3H), 1.27-1.15 (m, 4H), 1.14-1.01 (m, 2H); ¹³C NMR (100 MHz, CDCl₃):δ=159.5, 155.4, 149.9, 147.7, 147.4, 144.0, 116.0, 112.5, 111.4, 47.3,43.6, 39.7, 36.1, 36.0, 33.0, 31.9, 30.2, 23.8; HRMS (ESI) forC₂₀H₂₆N₄O₃ [M+H]⁺ calcd: 371.2083, found: 371.2093.

1-(Pyridin-4-yl)-3-(4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)urea(FEI-208)

Obtained from amine 21c (40.0 mg, 0.15 mmol) and phenylpyridin-4-ylcarbamate (32.2 mg, 0.15 mmol) according to the sameprocedure as that used to prepare FEI-154. Yield: 54.5 mg (94%,MW=386.1776), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.75 (brs, 1H,N—H), 8.31 (brs, 2H), 7.46 (d, 1H, J=5.0 Hz), 7.34-7.29 (m, 2H),7.28-7.26 (m, 1H), 7.07 (t, 1H, J=3.8 Hz), 6.10-6.0 (m, 1H, N—H),4.63-4.23 (m, 2H), 3.22 (q, 2H, J=6.1 Hz), 3.11-2.84 (m, 2H), 1.80-1.68(m, 2H), 1.58-1.42 (m, 3H), 1.35-1.23 (m, 4H), 1.16 (qd, 2H, J=12.4 Hz,3.5 Hz); ¹³C NMR (100 MHz, CDCl₃): δ=163.8, 155.4, 149.8, 147.7, 136.0,128.7, 128.6, 126.9, 112.5, 47.8, 44.0, 39.8, 36.0 (2C), 32.6, 31.9,30.2, 23.8; HRMS (ESI) for C₂₀H₂₆N₄O₂S [M+H]⁺ calcd: 387.1855, found:387.1858.

1-(4-(1-(2,6-Dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridin-4-yl)urea(FEI-209)

Obtained from amine 21d (48.0 mg, 0.15 mmol) and phenylpyridin-4-ylcarbamate (32.2 mg, 0.15 mmol), according to the sameprocedure as that used to prepare FEI-154. Yield: 40.8 mg (61.8%,MW=440.2424), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.60 (s, 1H, N—H),8.40-7.92 (m, 2H), 7.21 (t, 1H, J=8.4 Hz), 7.14-7.04 (m, 2H), 6.48 (dd,2H, J=8.3 Hz, 6.0 Hz), 5.99 (t, 1H, J=4.7 Hz, N—H), 4.69 (d, 1H, J=13.0Hz), 3.70 (s, 3H), 3.67 (s, 3H), 3.42 (d, 1H, J=13.5 Hz), 3.12 (q, 2H,J=5.8 Hz), 2.91 (td, 1H, J=12.4 Hz, 1.8 Hz), 2.72 (td, 1H, J=12.5 Hz,2.6 Hz), 1.80-1.71 (m, 1H), 1.56-1.47 (m, 1H), 1.46-1.35 (m, 3H),1.30-1.19 (m, 4H), 1.10 (qd, 2H, J=12.0 Hz, 3.5 Hz); ¹³C NMR (100 MHz,CDCl₃): δ=166.0, 156.5, 155.4, 149.6, 147.7, 130.8, 113.9, 112.4, 103.8,55.9, 47.3, 42.1, 39.7, 36.2, 36.1, 33.0, 31.6, 30.2, 23.9; HRMS (ESI)for C₂₄H₃₂N₄O₄ [M+H]⁺ calcd: 441.2502, found: 441.2499.

General Procedure for the Synthesis of FEI 210-213.

1-(4-(1-Benzoylpiperidin-4-yl)butyl)-3-(pyridin-3-yl)thiourea (FEI-210)

A solution of amine 21a (39.0 mg, 0.15 mmol) in CH₂Cl₂ (1.0 mL) wascooled to 0° C., 3-isothiocyanatopyridine (20.4 mg, 0.15 mmol) in CH₂Cl₂(0.5 mL) was added drop-wise, then the mixture was stirred at 20° C. for3 h. The solvent was evaporated in vacuo, and the resulting residue waspurified by FC (1/12 MeOH/EtOAc) to give FEI-210.

Yield: 46.7 mg (78.6%, MW=396.1984), white foam. ¹H NMR (400 MHz,CDCl₃): δ=8.91-8.65 (m, 1H, N—H), 8.38 (s, 2H), 7.94 (t, 1H, J=7.7 Hz),7.45-7.34 (m, 5H), 7.29-7.23 (m, 1H), 7.05-6.86 (m, 1H, N—H), 4.67 (d,1H, J=9.5 Hz), 3.74 (d, 1H, J=11.2 Hz), 3.62-3.52 (m, 2H), 3.01 (t, 1H,J=11.7 Hz), 2.78 (t, 1H, J=10.8 Hz), 1.87-1.77 (m, 1H), 1.69-1.60 (m,1H), 1.59-1.48 (m, 3H), 1.38-1.26 (m, 4H), 1.23-1.05 (m, 2H); ¹³C NMR(100 MHz, CDCl₃): δ=181.5, 170.6, 146.2, 145.3, 135.9, 135.4, 131.8,129.8, 128.6, 126.6, 123.5, 48.3, 44.8, 42.7, 35.9 (2C), 32.9, 31.9,29.0, 23.9; HRMS (ESI) for C₂₂H₂₈N₄OS [M+H]⁺ calcd: 397.2062, found:397.2062.

1-(4-(1-(Furan-2-carbonyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)thiourea(FEI-2-yl)

Obtained from amine 21b (37.5 mg, 0.15 mmol) and3-isothiocyanatopyridine (20.4 mg, 0.15 mmol) according to the sameprocedure as that used to prepare FEI-210. Yield: 56.3 mg (97.2%,MW=386.1776), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.64 (brs, 1H,N—H), 8.49 (d, 1H, J=2.1 Hz), 8.42 (dd, 1H, J=4.7 Hz. 1.2 Hz), 8.0-7.95(m, 1H), 7.48-7.46 (m, 1H), 7.32 (dd, 1H, J=8.2 Hz, 4.8 Hz), 6.94-6.89(m, 1H), 6.84 (t, 1H, J=5.3 Hz, N—H), 6.49 (dd, 1H, J=3.4 Hz, 1.8 Hz),4.62-4.38 (m, 2H), 3.64 (q, 2H, J=5.9 Hz), 3.24-2.96 (m, 1H), 2.95-2.67(m, 1H), 1.83-1.74 (m, 2H), 1.66-1.51 (m, 3H), 1.44-1.26 (m, 4H),1.25-1.14 (m, 2H); ¹³C NMR (100 MHz, CDCl₃): δ=181.5, 159.4, 147.5,146.6, 145.6, 143.9, 135.0, 132.1, 123.7, 115.8, 111.3, 47.2, 45.0,43.5, 36.1, 36.0, 32.8, 32.0, 29.1, 23.9; HRMS (ESI) for C₂₀H₂₆N₄O₂S[M+H]⁺ calcd: 387.1855, found: 387.1856.

1-(Pyridin-3-yl)-3-(4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)thiourea(FEI-212)

Obtained from amine 21c (40.0 mg, 0.15 mmol) and3-isothiocyanatopyridine (20.4 mg, 0.15 mmol) according to the sameprocedure as that used to prepare FEI-210. Yield: 58.4 mg (96.8%,MW=402.1548), white foam. ¹H NMR (400 MHz, CDCl₃): δ=8.63 (brs, 1H,N—H), 8.44 (d, 1H, J=2.2 Hz), 8.40 (dd, 1H, J=4.6 Hz, 1.2 Hz), 7.95 (dt,1H, J=8.2 Hz, 1.4 Hz), 7.45 (dd, 1H, J=5.0 Hz, 0.9 Hz), 7.30 (dd, 1H,J=8.3 Hz, 4.7 Hz), 7.28 (dd, 1H, J=3.6 Hz, 0.9 Hz), 7.05 (dd, 1H, J=5.0Hz, 3.7 Hz), 6.85 (t, 1H, J=5.4 Hz, N—H), 4.61-4.23 (m, 2H), 3.62 (q,2H, J=5.2 Hz), 3.11-2.83 (m, 2H), 1.83-1.72 (m, 2H), 1.63-1.55 (m, 3H),1.42-1.29 (m, 4H), 1.19 (qd, 2H, J=12.4 Hz, 3.7 Hz); ¹³C NMR (100 MHz,CDCl₃): δ=181.5, 163.7, 146.5, 145.5, 137.0, 135.1, 132.0, 128.7, 128.6,126.9, 123.7, 47.4, 44.9, 43.6, 36.1, 36.0, 32.7, 32.2, 29.1, 23.9; HRMS(ESI) for C₂₀H₂₆N₄OS₂ [M+H]⁺ calcd: 403.1626, found: 403.1627.

1-(4-(1-(2,6-Dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)thiourea(FEI-213)

Obtained from amine 21d (48.0 mg, 0.15 mmol) and3-isothiocyanatopyridine (20.4 mg, 0.15 mmol) according to the sameprocedure as that used to prepare FEI-210. Yield: 65.8 mg (96.2%,MW=456.2195), white foam. ¹H NMR (400 MHz, CDCl₃): δ=9.02-8.87 (m, 1H,N—H), 8.32 (d, 1H, J=2.9 Hz), 8.24 (brs, 1H), 8.09 (d, 1H, J=7.3 Hz),7.32-7.20 (m, 3H), 6.54 (t, 2H, J=9.2 Hz), 4.79 (d, 1H, J=12.7 Hz), 3.78(s, 3H), 3.72 (s, 3H), 3.59 (q, 2H, J=4.3 Hz), 3.50 (d, 1H, J=13.2 Hz),2.99 (t, 1H, J=12.8 Hz), 2.82 (t, 1H, J=12.8 Hz), 1.92-1.83 (m, 1H),1.63-1.49 (m, 4H), 1.45-1.26 (m, 4H), 1.19 (q, 2H, J=12.9 Hz); ¹³C NMR(100 MHz, CDCl₃): δ=181.6, 166.0, 156.5, 145.5, 144.8, 136.0, 131.1,130.7, 123.1, 113.9, 103.9, 55.8, 47.3, 44.6, 42.0, 36.2, 36.0, 33.0,31.7, 29.1, 24.0; HRMS (ESI) for C₂₄H₃₂N₄O₃S [M+H]⁺ calcd: 457.2273,found: 457.2277.

Alternative Synthesis of aryl- andheteroaryl[4-(4-aminobutyl)piperidine-1-yl]methanones

Reduction of commercial 4-(piperidin-4-yl)butanoic acid using LiAlH₄ asa reducing agent in dry THF, followed by N-protection of the free aminogroup with Boc₂O gave alcohol 6. Subsequent tosylation with TsCl in drypyridine followed by N-deprotection by acid treatment with 20% CF₃COOHin CH₂Cl₁₂ furnished 4-(piperidin-4-yl)butyl 4-methylbenzenesulfonate 36in quantitative yield. This compound was N-acylated with benzoyl,thiophene-2-carbonyl, 2-furoyl and 2,6-dimethoxybenzoyl chloride in thepresence of Et₃N to give compounds 37a-d. In the case of the5-hydroxymethyl-2-methyl-3. furoyl derivative the N-acylation wasperformed with the corresponding carboxylic acid 39 and PyBOP/DIPEA ascoupling agents. On its side, 39 was prepared from2-methyl-5-(D-arabino-tetrahydroxybutyl), ethyl ester, by glycoloxidation with NaIO₄, followed by aldehyde reduction and hydrolysis ofthe ethyl ester. Problems with the purification of these compoundslowered the yield of the coupling reaction. Finally, displacement of thetosyl group by azide and subsequent Staudinger reduction gave thecompounds the primary amines 41a-e.

Procedures Synthesis of tert-Butyl4-(4-tosyloxybutyl)piperidine-1-carboxylate (35)

To a solution of compound 6 (148.5 mg, 0.58 mmol) in dry pyridine (3 mL)cooled to 0° C., TsCl (445 mg, 2.31 mmol) was slowly added. The reactionwas stirred at room temperature for 3.5 h. Then, the mixture was cooledto 0° C. Water was added and the mixture was stirred at room temperaturefor 10 min. After evaporation of the solvent, the residue was dissolvedin AcOEt and washed with sat. aq. sol. of NaHCO₃ and brine. The driedorganic phase was evaporated to dryness. Purification by FC (1/4EtOAc:cyclohexane), gave 35 Yield: (189.3 mg, 0.46 mmol, 80%, MW:411.557) as a colorless oil. IR (v cm⁻¹) 1685 (C═O). ¹H-NMR (300 MHz,CDCl₃, δ ppm, J Hz) δ 7.80-7.77 (m, 2H, H-arom.), 7.35-7.32 (m, 2H,H-arom.), 4.06-4.04 (m, 2H, H-6a, H-2a), 4.02 (t, 2H, J_(4′,3′)=6.6,H-4′), 2.63 (td, 2H, J_(6b,5)=J_(2b,3)=3, J_(6b, 6a)=J_(2b, 2a)=13.2,H-6b, H-2b), 2.44 (s, 3H, Me), 1.67-1.56 (m, 4H, H-5a, H-3a, H-3′), 1.45(s, 9H, —C(CH₃)₃), 1.37-1.23 (m, 3H, H-4, H-2′), 1.20-1.12 (m, 2H,H-1′), 1.08-0.94 (m, 2H, H-5b, H-3b). ¹³C-NMR (75.4 MHz, CDCl₃, 6 ppm)155.0 (C═O), 144.8, 133.4, 129.9, 128.0 (C-arom.), 79.3 (—C(CH₃)₃), 70.6(C-4′), 44.0 (C-6, C-2), 35.9 (C-4), 35.8 (C-1′), 32.1 (C-5, C-3), 29.1(C-3′), 28.6 (—C(CH₃)₃), 22.6 (C-2′), 21.8 (Me). CIMS m/z 412 [10%,(M+H)⁺], 338 [67%, (M-OC(CH₃)₃)⁺]. HRCIMS m/z found 412.2155, calc. forC₂₁H₃₄O₅NS: 412.2158.

Synthesis of 1-benzoyl-4-(4-tosyloxybutyl)piperidine (37a)

Compound 35 (877.3 mg, 2.13 mmol) was dissolved in 20% CF₃COOH/CH₂Cl₂(15 mL) and the mixture was stirred at room temperature for 2.5 h andthen the solvent was evaporated in vacuo. Triethyl amine (10.67 mmol,1.5 mL) and benzoyl chloride (2.77 mmol) were subsequently added underN₂ atmosphere, to a cooled (0° C.) solution of the residue in dry CH₂Cl₂(9 mL). After 2.5 h, the reaction was worked up by dilution withsaturated aqueous. NH₄Cl and extracted with CH₂Cl₂ (15 mL, 3 times). Theorganic phases were combined and washed with brine, dried (MgSO₄),filtered and concentrated in vacuo to dryness. The residue was purifiedby FC (EtOAc/cyclohexane, 1/2→1/1→2/1). Yield: (831.1 mg, 2.00 mmol,94%, MW: 415.548) as a colourless oil. IR (v cm⁻¹) 1625 (C═O). ¹H-NMR(300 MHz, CDCl₃, δ ppm, J Hz) δ 7.79-7.77 (m, 2H, H-arom. Ts), 7.38(brs, 5H, H-arom. Ph), 7.35-7.32 (m, 2H, H-arom. Ts), 4.66 (brs, 1H,H-2a)*, 4.02 (t, 2H, J_(4′,3′)=6.6, H-4′), 3.75 (brs, 1H, H-6a)*, 2.85(brs, 2H, H-6b, H-2b), 2.45 (s, 3H, Me), 1.74-1.59 (m, 4H, H-3′, H-3a,H-5a), 1.47-1.1 (m, 7H, H-4, H-2′, H-1′, H-3b, H-5b). (*) These protonscould be exchanged. ¹³C-NMR (75.4 MHz, CDCl₃, δ ppm) 170.4 (C═O), 144.8,136.5, 133.3, 130.0, 129.7, 128.5, 128.0, 126.9 (C-arom.), 70.5 (C-4″),47.7 (C-2 or C-6), 42.7 (C-6 or C-2), 36.1 (C-4), 35.8 (C-1′), 32.5(C-3, C-5), 29.1 (C-3′), 22.6 (C-2′), 21.8 (Me). CIMS m/z 416 [100%,(M+H)⁺], 417 [27%, (M+2H)+]. HRCIMS m/z found 416.1887, calc. forC₂₃H₃₀O₄NS: 416.1896.

1-(thiophene-2-carbonyl)-4-(4-tosyloxybutyl)-2-yl)piperidine (37b)

Same procedure as that applied for the preparation of 37a, starting with35 and thiophene-2-carbonyl chloride. Yield: (763 mg, 1.81 mmol, 85%,MW: 421.570) as a yellow oil. IR (v cm⁻¹) 1608 (C═O). ¹H-NMR (300 MHz,CDCl₃, δ ppm, J Hz) δ 7.80-7.77 (m, 2H, H-arom. Ts), 7.41 (dd, 1H,J_(5″,4″)=5.1, J_(5″,3″)=1.2, H-5″), 7.35-7.32 (m, 2H, H-arom. Ts), 7.25(dd, 1H, J_(3″,4″)=3.6, H-3″), 7.02 (dd, 1H, H-4″), 4.40 (brs, 2H, H-6a,H-2a), 4.02 (t, 2H, J_(4′,3′)=6.3, H-4′), 2.89 (m, 2H, H-6b, H-2b), 2.44(s, 3H, Me), 1.75-1.59 (m, 4H, H-3′, H-3a, H-5a), 1.51-1.28 (m, 3H, H-4,H-2′), 1.24-1.06 (m, 4H, H-1′, H-3b, H-5b). ¹³C-NMR (75.4 MHz, CDCl₃, δppm) 163.6 (C═O), 144.8, 137.6, 133.3, 129.9, 128.5, 128.3, 128.0, 126.7(C-arom.), 70.5 (C-4″), 45.8 (C-2, C-6), 36.1 (C-4), 35.7 (C-1′), 32.5(C-3, C-5), 29.1 (C-3′), 22.6 (C-2′), 21.7 (Me). CIMS m/z 422 [100%,(M+H)⁺], 423 [26%, (M+2H)+]. HRCIMS m/z found 422.1456, calc. forC₂₁H₂₈O₄NS₂: 422.1460.

1-(2-furoyl)-4-(4-tosyloxybutyl)-2-yl)piperidine (37c)

Same procedure as that applied for the preparation of 37a, starting with35 and 2-furoyl chloride. Yield: (758.3 mg, 1.87 mmol, 88%, MW: 405.509)as a pale yellow oil. IR (v cm⁻¹) 1616 (C═O). ¹H-NMR (300 MHz, CDCl₃, δppm, J Hz) δ 7.78 (d, 2H, J_(H,H)=8.1, H-arom. Ts), 7.56 (d, 1H,J_(5″,4″)=0.9, H-5″), 7.33 (d, 2H, J_(H,H)=8.4, H-arom.Ts), 6.91 (d, 1H,J_(3″,4″)=3.3, H-3″), 6.45 (dd, 1H, H-4″), 4.48 (brs, 2H, H-6a, H-2a),4.02 (t, 2H, J_(4′,3′)=6.3, H-4′), 2.87 (brs, 2H, H-6b, H-2b), 2.43 (s,3H, Me), 1.73-1.59 (m, 4H, H-3′, H-3a, H-5a), 1.51-1.27 (m, 3H, H-4,H-2′), 1.24-1.1 (m, 4H, H-1′, H-3b, H-5b). ¹³C-NMR (75.4 MHz, CDCl₃, δppm) 159.3 (C═O), 148.2, 144.8, 143.5, 133.3, 129.9, 127.9, 115.7, 111.2(C-arom.), 70.5 (C-4″), 49.5 (C-2, C-6), 36.1 (C-4), 35.7 (C-1′), 32.5(C-3, C-5), 29.1 (C-3′), 22.6 (C-2′), 21.7 (Me). CIMS m/z 406 [100%,(M+H)⁺], 234 [30%, (M+H-OTs)⁺]. HRCIMS m/z found 406.1678, calc. forC₂₁H₂₅O₅NS: 406.1688.

1-(2,6-dimethoxybenzoyl)-4-(4-tosyloxybutyl)piperidine (37d)

Same procedure as that applied for the preparation of 37a, starting with35 and 2,6-dimethoxybenzoyl chloride. Yield: (435.6 mg, 0.916 mmol, 43%,MW: 475.600) as a pale yellow oil. ¹H-NMR (300 MHz, CDCl₃, δ ppm, J Hz)δ 7.83 (d, 2H, J_(H,H)=8.3, H-arom. Ts), 7.39 (d, 2H, J_(H,H)=8.2,H-arom. Ts), 7.29 (t, 1H, J_(H,H)=6.8, H-arom.), 6.61 (d, 1H, H-arom.),6.58 (d, 1H, H-arom.), 4.86-4.77 (m, 1H, H-6a or H-2a), 4.07 (t, 2H,J_(4′,3′)=6.4, H-4′), 3.84 (s, 3H, OCH₃), 3.83 (s, 3H, OCH₃), 3.52-3.46(m, 1H, H-6a or H-2a), 2.94 (td, 1H, J_(H,H)=13.2, J_(H,H)=3.2, H-6b orH-2b), 2.76 (td, 1H, J_(H,H)=12.7, J_(H,H)=2.9, H-6b or H-2b), 2.49 (s,3H, CH₃), 1.68-0.90 (m, 11H, H-3, H-4, H-5, H-1′, H-2′, H-3′). ¹³C-NMR(75.4 MHz, CDCl₃, δ ppm) δ 165.3 (C═O), 156.8, 156.7, 144.9, 133.3,130.1, 130.0, 128.0, 115.2, 104.1 (C-arom.), 70.6 (C-4′), 56.0 (OCH₃),55.9 (OCH₃), 47.0, 41.7 (C-2, C-6), 36.2, 35.6, 32.8, 32.0, 29.1, 22.7(C-3, C-5, C-4, C-3′, C-2′, C-1′), 21.8 (CH₃).

Ethyl 5-formyl-2-methylfuran-3-carboxylate (38)

To a solution of ethyl2-methyl-5-(D-arabino-tetrahydroxybutyl)furan-3-carboxylate (2.91 g,10.61 mmol) [a) Robina, I.; Moreno-Vargas, A. J.; Fernandez-Bolanos, J.G.; F., Jose; Demange, R.; Vogel, P. Bioorg. & Med. Chem. Lett. 2001,11, 2555-2559. b) Bartoli, G.; Fernandez-Bolanos, J. G.; Di Antonio, G.;Foglia, G.; Giuli, S.; Gunnella, R.; Mancinelli, M.; Marcantoni, E.;Paoletti, M. J. Org. Chem. 2007, 72, 6029-6036] in MeOH (40 mL) at 0° C.was added slowly a solution of NaIO₄ (5.22 g, 24.40 mmol) in water (30mL). The mixture was stirred at room temperature for 40 min. Afterevaporation of the solvent, the residue was diluted with CH₂Cl₂ andwashed with water and brine. The organic phases were dried, filtered andconcentrated. The residue was purified by FC (1/3 EtOAc/cyclohexane) togive 38 (1.66 g, 9.14 mmol, 86%, MW: 182.18) as white solid. IR (v cm⁻¹)1710 (C═O), 1684, 1590 (C═C). ¹H NMR (300 MHz, CDCl₃, 8 ppm, J Hz) δ9.54 (s, 1H, CHO), 7.46 (s, 1H, H-3), 4.31 (q, 2H, ²J_(H,H)=7.2,—CH₂CH₃), 2.67 (s, 3H, Me), 1.35 (t, 3H, —CH₂CH₃). ¹³C NMR (75.4 MHz,CDCl₃, δ ppm) δ 177.2 (CHO), 164.8 (COOEt), 162.7 (C-5), 150.4 (C-2),122.6 (C-3), 116.6 (C-4), 61.0 (—CH₂CH₃), 14.4 (Me), 14.4 (—CH₂CH₃).CIMS m/z 183 [100%, (M+H)⁺], 182 [32%, (M)⁺]. HRCIMS m/z found 183.0653,calc. for C₉H₁₁O₄: 183.0657.

5-Hydroxymethyl-2-methylfuran-3-carboxylic acid (39)

To a solution of 38 (1.64 g, 9.01 mmol) in MeOH, NaBH₄ (682 mg, 18.02mmol) was added. The mixture was stirred at room temperature for 30 min.The mixture was neutralized with citric acid. After evaporation ofsolvent, the residue was diluted with CH₂Cl₂ and washed with water. Theorganic phases were dried, filtered and concentrated to give ethyl5-hydroxymethyl-2-methylfuran-3-carboxylic ester (1.39 g, 7.54 mmol,84%, MW: 184.191) as a white solid. IR (v cm⁻¹) 3423 (OH), 1710 (C═O).¹H NMR (300 MHz, CDCl₃, 8 ppm, J Hz) δ 6.52 (s, 1H, H-3), 4.53 (s, 1H,H-1′), 4.26 (q, 2H, ²J_(H,H)=6.9, —CH₂CH₃), 2.55 (s, 3H, Me), 1.33 (t,3H, —CH₂CH₃). ¹³C NMR (75.4 MHz, CDCl₃, 8 ppm) δ 177.2 (CHO), 164.8(COOEt), 162.7 (C-5), 150.4 (C-2), 122.6 (C-3), 116.6 (C-4), 61.0(—CH₂CH₃), 14.4 (Me), 14.4 (—CH₂CH₃). CIMS m/z 185 [46%, (M+H)⁺], 184[61%, (M)⁺], 167 [100%, (M-OH+H)⁺]. HRCIMS m/z found 184.0732, calc. forC₉H₁₂O₄: 184.0736. This ester (1.36 mg, 7.41 mmol) was dissolved in 1MNaOH/EtOH (30 mL) and the mixture was stirred at 60° C. for 5.5 h. Themixture was cooled to 0° C., neutralized with acid resin IR 120 (H+),filtered and concentrated to give 39 (1.10 g, 7.04 mmol, 95%, MW:156.137) as a white solid. IR (v cm⁻¹) 3330 (OH), 1665 (C═O). ¹H NMR(300 MHz, MeOD, δ ppm, J Hz) δ 6.50 (s, 1H, H-3), 4.45 (s, 1H, H-1′),2.54 (s, 3H, Me). ¹³C NMR (75.4 MHz, MeOD, δ ppm) δ 167.3 (—COOH), 160.4(C-5), 154.1 (C-2), 115.4 (C-4), 109.4 (C-3), 57.1 (C-1′), 13.7 (Me).CIMS m/z 158 [63%, (M+2H)⁺], 157 [65%, (M+H)⁺], 139 [100%, (M-OH+H)⁺].HRCIMS m/z found 157.0501, calc. for C₇H₉O₄: 157.0501.

1-(5-Hydroxymethyl-2-methyl-3-furoyl)-4-(4-tosyloxybutyl)piperidine(37e)

Compound 35(879.5 mg, 2.14 mmol) was dissolved in 20% CF₃COOH:CH₂Cl₂ (15mL) and the mixture was stirred at room temperature for 2 h. The solventwas evaporated. DIPEA (1.9 mL, 10.69 mmol), carboxylic acid 39 (440 mg,2.78 mmol) and PyBOP (1.93 g, 3.64 mmol) were added in succession to asolution of the residue in DMF (7 mL). The mixture was stirred overnightat 20° C. The solvent was evaporated in vacuo and the residue wasdissolved in EtOAc and washed with aqueous HCl (1M), then with asaturated aqueous. Solution of NaHCO₃ and, finally with water. Afterdrying (MgSO₄) the solvent was evaporated in vacuo. FC (19/1 diethylether/acetone), gave 37e (292 mg, 0.65 mmol, 30%, MW: 449.562) as a paleyellow oil. IR (v cm⁻¹) 3330 (OH), 1596 (C═O). ¹H NMR (300 MHz, CDCl₃, δppm, J Hz) δ 7.78 (d, 2H, J_(H,H)=8.4, H-arom. Ts), 7.34 (d, 2H,J_(H,H)=7.8, H-arom. Ts), 6.21 (s, 1H, H-1″), 4.54-4.09 (m, 4H, —CH₂OH,H-6a, H-2a), 4.02 (t, 2H, J_(4′,3′)=6.3, H-4′), 2.82 (brs, 2H, H-6b,H-2b), 2.45 (s, 3H, Me), 2.35 (s, 3H, Me), 1.90 (br. s, 1H, OH),1.70-1.59 (m, 4H, H-3′, H-3a, H-5a), 1.49-1.0 (m, 7H, H-4, H-2′, H-1′,H-3b, H-5b). ¹³C-NMR (75.4 MHz, CDCl₃, δ ppm) 165.0 (C═O), 153.1, 151.9,144.9, 133.3, 130.0, 128.0, 120.4, 116.8, 108.4 (C-arom.), 70.5 (C-4″),57.4 (—CH₂OH), 45.2 (C-2, C-6), 36.1 (C-4), 35.8 (C-1′), 32.5 (C-3,C-5), 29.1 (C-3′), 22.6 (C-2′), 21.8 (CH₃), 13.1 (CH₃). LSIMS m/z 472[64%, (M+Na)⁺]. HRLSIMS m/z found 472.1765, calc. for C₂₃H₃₁O₆NSNa:472.1770.

4-(4-Azidobutyl)-1-benzoylpiperidine (40a)

To a solution of 37a (326 mg, 0.785 mmol) in DMF (4 mL), NaN₃ (153 mg,2.355 mmol) was added. The reaction was stirred at 70° C. for 3 to 4 h(TLC monitoring). After cooling to room temperature the solvent wasevaporated and the residue was dissolved in CH₂Cl₂ and washed with waterand brine. The dried organic phase was evaporated and the residue waspurified by FC (EtOAc/cyclohexane, 1/3→1/2), to give 40a. Yield: (202.3mg, 0.71 mmol, 90%, MW: 286.379) as a pale yellow oil. The NMR data werein accordance with date from the literature given for this compound[Galli, U.; Ercolano, E.; Carraro, L.; Roman, C. R. B.; Sorba, G.;Canonico, P. L.; Genazzani, A. A.; Tron, G. C.; Billington, R. A.ChemMedChem, 2008, 3, 771-779].

4-(4-Azidobutyl)-1-(thiophene-2-carbonyl)piperidine (40b)

Same procedure as for the preparation of 40a starting with 37b (331 mg,0.785 mmol). Yield: (208.8 mg, 0.714 mmol, 91%, MW: 292.401) as a paleyellow oil. IR (v cm⁻¹) 2090 (N₃), 1610 (C═O). ¹H-NMR (300 MHz, CDCl₃, δppm, J Hz) δ 7.41 (dd, 1H, J_(5″4′)=4.8, J_(5″,3″)=1.2, H-5″), 7.26 (dd,1H, J_(3″,4″)=3.3, H-3″), 7.02 (dd, 1H, H-4″), 4.41 (m, 2H, H-2a, H-6a),3.27 (t, 2H, J_(4′,3′)=6.6, H-4′), 2.91 (m, 2H, H-2b, H-6b), 1.76 (br d,2H, H-3a, H-5a), 1.64-1.50 (m, 3H, H-4, H-3′), 1.46-1.38 (m, 4H, H-2′,H-1′), 1.26-1.13 (m, 2H, H-3b, H-5b). ¹³C-NMR (75.4 MHz, CDCl₃, δ ppm)163.6 (C═O), 137.7 (C-2″), 128.5 (C-5″), 128.3 (C-3″), 126.7 (C-4″),51.5 (C-4′), 46.7 (C-6, C-2), 36.2 (C-4), 36.0 (C-2), 32.6 (C-5, C-3),29.1 (C-3′), 23.9 (C-1). CIMS m/z 293 [83%, (M+H)⁺], 292 [19%, (M)⁺].HRCIMS m/z found 293.1431, calc. for C₁₄H₂₁ON₄S: 293.1436.

4-(4-Azidobutyl)-1-(2-furoyl)piperidine (40c)

Same procedure as for the preparation of 40a starting with 37c. (318.3mg, 0.785 mmol). Yield: (212.6 mg, 0.769 mmol, 98%, MW: 276.340) as apale yellow oil. IR (v cm⁻¹) 2091 (N₃), 1618 (C═O). ¹H-NMR (300 MHz,CDCl₃, δ ppm, J Hz) δ 7.45 (dd, 1H, J₅-4=1.5, J_(5″-3″)=0.6, H-5″), 6.91(dd, 1H, J_(3″-4″)=3.3, H-3″), 6.44 (dd, 1H, H-4″), 4.49 (m, 2H, H-2a,H-6a), 3.26 (t, 2H, J_(4″-3″)=6.9, H-4′), 2.89 (m, 2H, H-2b, H-6b), 1.76(br d, 2H, H-3a, H-5a), 1.63-1.50 (m, 1H, H-4), 1.45-1.39 (m, 4H, H-3′,H-1′), 1.37-1.27 (m, 2H, H-2′), 1.25-1.13 (m, 2H, H-3b, H-5b). ¹³C-NMR(75.4 MHz, CDCl₃, δ ppm) 159.3 (C═O), 148.3 (C-2″), 143.5 (C-5″), 115.7(C-3″), 111.2 (C-4″), 51.5 (C-4′), 44.9 (C-6, C-2), 36.2 (C-4), 36.0(C-2), 32.6 (C-5, C-3), 29.1 (C-3′), 23.9 (C-1). CIMS m/z 277 [59%,(M+H)⁺]. HRCIMS m/z found 277.1670, calc. for C₁₄H₂₁O₂N₄: 277.1665.

4-(4-Azidobutyl)-1-(2,6-dimethoxybenzoyl)piperidine (40d)

Same procedure as for the preparation of 40a starting with 37d. (373.3mg, 0.785 mmol). Yield: (174.0 mg, 0.502 mmol, 64%, MW: 346.431) as apale yellow oil. IR (v cm⁻¹) 2092 (N₃), 1633 (C═O). ¹H-NMR (300 MHz,CDCl₃, δ ppm, J Hz) δ 7.29 (t, 1H, J_(H,H)=8.3, H-arom.), 6.60 (d, 1H,H-arom.), 6.59 (d, 1H, H-arom.), 4.88-4.80 (m, 1H, H-6a or H-2a), 3.85(s, 3H, OCH₃), 3.83 (s, 3H, OCH₃), 3.55-3.46 (m, 1H, H-6a or H-2a), 3.31(t, 2H, J_(4′,3′)=6.8, H-4′), 2.96 (td, 1H, J_(H,H)=12.8, J_(H,H)=2.6,H-6b or H-2b), 2.78 (td, 1H, J_(H,H)=12.8, J_(H,H)=2.9, H-6b or H-2b),1.84-1.08 (m, 11H, H-3, H-4, H-5, H-1′, H-2′, H-3′). ¹³C-NMR (75.4 MHz,CDCl₃, δ ppm) δ 165.2 (C═O), 156.8, 156.7, 130.0, 115.2, 104.1(C-arom.), 56.0 (OCH₃), 55.9 (OCH₃), 51.5 (C-4′), 47.0, 41.8 (C-2, C-6),36.3, 36.1, 32.9, 32.1, 29.2, 24.0 (C-3, C-5, C-4, C-3′, C-2′, C-1′).HRESIMS m/z found 347.2073 calc. for C₁₈H₂₇O₃N₄: 347.2078.

4-(4-Azidobutyl)-1-[5-(hydroxymethyl)-2-methyl-3-furoyl]piperidine (40e)

Same procedure as for the preparation of 40a starting with 37e (352.9mg, 0.785 mmol). Yield: (216.3 mg, 0.675 mmol, 86%, MW: 320.393) as apale yellow oil. IR (v cm⁻¹) 3369 (OH), 2091 (N₃), 1600 (C═O). ¹H NMR(300 MHz, CDCl₃, δ ppm, J Hz) δ 6.20 (s, 1H, H-1″), 4.74-3.73 (m, 4H,—CH₂OH, H-2a, H-6a), 4.02 (t, 2H, J_(4′,3′)=6.9, H-4′), 2.80 (br.s, 2H,H-2b, H-6b), 2.34 (s, 3H, Me), 1.74-1.71 (m, 2H, H-3a, H-5a), 1.63-1.56(m, 1H, H-3′), 1.52-1.34 (m, 3H, H-4, H-2′), 1.31-1.24 (m, 2H, H-1′),1.13-1.09 (m, 2H, H-3b, H-5b). ¹³C-NMR (75.4 MHz, CDCl₃, δ ppm) 165.1(C═O), 153.0, 152.0, 116.7, 108.3, (C-arom.), 57.3 (—CH₂OH), 51.4(C-4′), 42.7 (C-2, C-6), 36.2 (C-4), 35.9 (C-1′), 32.6 (C-3, C-5), 29.1(C-3′), 23.9 (C-2′), 13.1 (CH₃). CIMS m/z 321 [100%, (M+H)⁺]. HRCIMS m/zfound 321.1931, calc. for C₁₆H₂₅O₃N₄: 321.1927.

4-(4-Aminobutyl)-1-benzoylpiperidine (41a≡21a)

Water (40 μL, 2.18 mmol) and triphenylphosphine (143 mg, 0.55 mmol) wereadded to a solution of compounds 40a (104.1 mg, 0.36 mmol) in THF (1.5mL). The resulting mixture was heated at reflux for 6 to 8 h. Thesolvent was evaporated in vacuo and the residue was purified by FC(10/1/0.1 CH₂Cl₂/MeOH/NH₄OH). Yield: (91.1 mg, 0.35 mmol, 97%, MW:260.381) as a pale yellow oil. The NMR data were in accordance to thepreviously described compound.

4-(4-Aminobutyl)-1-(thiophene-2-carbonyl)piperidine (41b≡21c)

Same procedure as for the preparation of 41a starting with 40b. Yield:(92.2 mg, 0.346 mmol, 96%, MW: 266.403) as a pale yellow oil. IR (vcm⁻¹) 3364 (NH), 1604 (C═O). ¹H-NMR (300 MHz, CDCl₃, δ ppm, J Hz) δ 7.40(dd, 1H, J_(5″,4″)=4.8, J_(5″,3″)=0.9, H-5″), 7.25 (dd, 1H,J_(3″,4″)=3.6, H-3″), 7.01 (dd, 1H, H-4″), 4.40 (m, 2H, H-2a, H-6a),2.91 (m, 2H, H-2b, H-6b), 2.69 (t, 2H, J_(4′,3′)=5.7, H-4′), 1.75 (br d,2H, H-3a, H-5a), 1.56-1.1 (m, 11H, H-4, H-3′, H-2′, H-1′, NH₂, H-3b,H-5b). ¹³C-NMR (75.4 MHz, CDCl₃, δ ppm) 163.5 (C═O), 137.7 (0-2″), 128.5(0-3″), 128.2 (0-5″), 126.7 (0-4″), 46.5 (C-6, C-2), 42.2 (C-4′), 36.3(C-4), 36.3 (C-2′), 33.9 (C-3′), 32.6 (C-5, C-3), 24.0 (C-1′). CIMS m/z266 [100%, (M+H)⁺]. HRCIMS m/z found 267.1539, calc. for C₁₄H₂₃ON₂S:267.1531. This compound is identical to 21c.

4-(4-Aminobutyl)-1-(2-furoyl)piperidine (41c≡21b)

Same procedure as for the preparation of 41a starting with 40c. Yield:(79.3 mg, 0.317 mmol, 88%, MW: 250.342). IR (v cm⁻¹) 3359 (NH), 2927,1612 (C═O). ¹H-NMR (300 MHz, CDCl₃, δ ppm, J Hz) δ 7.43 (dd, 1H,J_(5″,4″)=1.8, J_(5″,3″)=0.9, H-5″), 6.88 (dd, 1H, J_(3″,4″)=3.3, H-3″),6.42 (dd, 1H, H-4″), 4.45 (brs, 2H, H-2a, H-6a), 2.88 (brs, 2H, H-2b,H-6b), 2.66 (t, 2H, J_(4′,3′)=6.6, H-4′), 1.94 (brs, 2H, NH₂), 1.73 (brd, 2H, H-3a, H-5a), 1.55-1.37 (m, 3H, H-4, H-3′), 1.35-1.09 (m, 6H,H-2′, H-1′, H-3b, H-5b). ¹³C-NMR (75.4 MHz, CDCl₃, δ ppm) 159.2 (C═O),148.2 (C-2″), 143.5 (C-5″), 115.6 (C-3″), 111.1 (C-4″), 46.5 (C-6, C-2),41.9 (C-4′), 36.3 (C-2′), 36.2 (C-4), 33.5 (C-3′), 32.6 (C-5, C-3), 23.9(C-1′). CIMS m/z 251 [100%, (M+H)⁺]. HRCIMS m/z found 251.1764, calc.for C₁₄H₂₃O₂N₂: 251.1760. This compound is identical to 21b.

4-(4-Aminobutyl)-N-(2,6-dimethoxybenzoyl)-piperidine (41d≡21d)

Same procedure as for the preparation of 41a starting with 40d. Yield:(89.9 mg, 0.28 mmol, 78%, MW: 320.433) as a pale yellow oil. ¹H-NMR (300MHz, CDCl₃, δ ppm, J Hz) δ 7.30 (t, 1H, J_(H,H)=8.3, H-arom.), 6.60 (d,1H, H-arom.), 6.59 (d, 1H, H-arom.), 4.88-4.78 (m, 1H, H-6a or H-2a),3.85 (s, 3H, OCH₃), 3.83 (s, 3H, OCH₃), 3.54-3.45 (m, 1H, H-6a or H-2a),2.96 (td, 1H, J_(H,H)=12.9, J_(H,H)=2.6, H-6b or H-2b), 2.83-2.72 (m,1H, H-6b or H-2b, H-4′), 1.87-1.07 (m, 11H, H-3, H-4, H-5, H-1′, H-2′,H-3′). ¹³C-NMR (75.4 MHz, CDCl₃, δ ppm) δ 165.2 (C═O), 156.8, 156.7,130.0, 115.2, 104.0 (C-arom.), 56.0 (OCH₃), 55.9 (OCH₃), 47.1 (C-2,C-6), 42.2 (C-4′), 41.8 (C-2, C-6), 36.4, 36.3, 33.8, 32.0, 32.1, 24.0(C-3, C-5, C-4, C-3′, C-2′, C-1′). HRESIMS m/z found 321.2168 calc. forC₁₈H₂₉O₃N₂: 321.2173.

4-(4-Aminobutyl)-1-(5-hydroxymethyl-2-methyl-3-furoyl)piperidine (41e)

Same procedure as for the preparation of 41a starting with 40e. Yield:(79.5 mg, 0.27 mmol, 75%, MW: 294.395). IR (v cm⁻¹) 3359 (OH, NH), 1600(C═O). ¹H NMR (300 MHz, CDCl₃, δ ppm, J Hz) δ 6.18 (s, 1H, H-1″), 4.52(s, 2H, —CH₂OH), 3.97 (br. s, 2H, H-2a or H-6a), 2.90 (br. s, 2H, H-2aor H-6a), 2.67 (t, 2H, J_(4′,3′)=6.9, H-4′), 2.33 (s, 3H, Me), 2.23(br.s, 4H, NH₂, H-2b, H-6b), 1.72-1.69 (m, 2H, H-3a, H-5a), 1.50-1.37(m, 3H, H-3′, H-4), 1.35-1.24 (m, 4H, H-2′, H-1′), 1.11-1.07 (m, 2H,H-3b, H-5b). ¹³C-NMR (75.4 MHz, CDCl₃, δ ppm) 165.1 (C═O), 152.8, 152.4,116.7, 108.1, (C-arom.), 57.0 (—CH₂OH), 47.7 (C-2, C-6), 42.0 (C-4′),36.3 (C-4 or C-2), 36.2 (C-4 or C-2), 33.5 (C-3′), 32 (C-5, C-3), 24.0(C-1′), 13.1 (CH₃). CIMS m/z 295 [100%, (M+H)⁺]. HRCIMS m/z found295.2024, calc. for C₁₆H₂₇O₃N₂: 295.2022.

Synthesis of 2,6-difluoro pyridine derivatives

(E)-tert-Butyl 3-(2,6-difluoropyridin-3-yl)acrylate (42)

To a 20 mL sealed tube, Pd(OAc)₂ (11.4 mg, 0.05 mmol),1,10-phenanthroline (12 mg, 0.065 mmol), Ag₂CO₃ (69.6 mg, 0.25 mmol),tert-butylacrylate (75 μL, 0.5 mmol) and 2,6-difluoropyridine (0.73 mL,8 mmol) and DMF (1 mL) were added. The tube was capped and stirred at140° C. for 12 h. The reaction mixture was cooled to room temperatureand diluted with EtOAc, filtered through a short pad of Cellite, washedwith EtOAc and concentrated in vacuo. The residue was purified by FC(1/10 EtOAc/cyclohexane) to give 42 (53 mg, 0.22 mmol, 44%, MW: 241.238)as yellow solid. IR (v cm⁻¹) 1698 (C═O). ¹H NMR (300 MHz, CDCl₃, δ ppm,J Hz) δ 8.01-7.98 (m, 1H, H-arom.), 7.57 (d, 1H, J_(H,H′)=16.2, CH═CH),6.87 (dd, 1H, J_(H,H)=8.4, J_(H,H)=3.3, H-arom.), 6.44 (d, 1H, CH═CH).¹³C NMR (75.4 MHz, CDCl₃, δ ppm) δ 165.5 (C═O), 161.7 (dd,J_(C-F)=250.1, J_(C-F)=14.4, C-F), 159.3 (dd, J_(C-F)=252.5J_(C-F)=14.4, C-F), 143.5 (dd, J_(C-F)=8.1, J_(C-F)=3.9, C-arom.), 133.3(d, J_(C-F)=2.5, CH═CH), 124.6 (dd, J_(C-F)=5.7, J_(C-F)=2.3, CH═CH),114.9 (dd, J_(C-F)=24.3, J_(C-F)=6.1, C-arom.), 1087.1 (dd,J_(C-F)=34.8, J_(C-F)=5.7, C-arom.), 81.4 (—C(CH₃)₃), 28.2 (—C(CH₃)₃).HRCIMS m/z obsd. 242.0988, calc. for Cl₂H₁₄O₂NF₂: 242.0993.

(E)-3-(2, 6-difluoropyridin-3-yl)acrylic acid (43)

Trifluoroacetic acid (2 mL) was added to 42 (263.9 mg, 1.09 mmol)dissolved in CH₂Cl₂ (8 mL) and the mixture was stirred at 20° C. for 3 hunder Ar atmosphere. Solvent evaporation in vacuo gave 43 (201.8 mg,1.09 mmol, quant. MW: 185.130) as a yellow solid. IR (vcm⁻¹) 2927 (OH),1682 (C═O), 1464, 1218, 996, 732. ¹H NMR (300 MHz, MeOD, δ ppm, J Hz) δ8.36 (m, 1H, H-arom.), 7.67 (d, 1H, J_(H,H′)=15.9, CH═CH), 7.05 (dd, 1H,J_(H,H)=8.4, J_(H,H)=2.7, H-arom.), 6.60 (d, 1H, CH═CH). ¹³C NMR (75.4MHz, MeOD, δ ppm) δ 164.9 (C═O), 163.1 (dd, J_(C-F)=248.5, J_(C-F)=14.6,C-F), 160.4 (dd, J_(C-F)=250.1, J_(C)-F=14.5, C-F), 145.7 (dd,J_(C-F)=8.4, J_(C-F)=3.7, C-arom.), 135.5 (d, J_(C-F)=1.7, CH═CH), 123.8(dd, J_(C-F)=5.1, J_(C-F)=2.1, CH═CH), 115.9 (dd, J_(C-F)=24.1,J_(C-F)=6.0, C-arom.), 108.3 (dd, J_(C-F)=35.2, J_(C-F)=5.7, C-arom.).HRCIMS m/z obsd. 186.0367, calc. for C₈H₆O₂NF₂: 186.0367.

General Procedure for the Synthesis of PER-201, PER-202, PER-203, MPM-09

Amide coupling reactions between carboxylic acid 43 and amines 41a-dand, were carried out using PyBOP and DIPEA as coupling agents giving ingood yields the following difluorinated compounds: PER-201 (MW=427.496),PER-202 (MW=433.518), PER-203 (MW=417.457) and MPM-09 (MW=487.548),respectively.

(E)-N-(4-(1-benzoylpiperidin-4-yl)butyl)-3-(2,6-difluoropyridin-3-yl)acrylamide(PER-201)

To a solution of 41a (0.19 mmol) in DMF (1 mL), DIPEA (0.13 mL, 0.76mmol), 43 (52.5 mg, 0.28 mmol) and PyBOP (151 mg, 0.28 mmol) were added.The reaction mixture was stirred at 20° C. for 15 h. The solvent wasevaporated and the resulting crude was dissolved in EtOAc. The organicphase was washed with 1 M aqueous HCl, then with a saturated aqueoussolution of NaHCO₃ and water. After drying (MgSO₄) the solvent wasevaporated in vacuo and the residue purified by FC (6/1 diethylether/acetone) to give PER-201. Yield: (71.4 mg, 0.167 mmol, 88%, MW:427.496), pale yellow oil. IR (v cm⁻¹) 3276 (NH), 1605 (C═O). ¹H NMR(300 MHz, CDCl₃, δ ppm, J Hz) δ 7.98-7.90 (m, 1H, H-arom.), 7.54 (d, 1H,J_(H,H)=15.9, CH═CH), 7.51 (s, 5H, H-arom.), 6.85 (dd, 1H, J_(H,H)=8.1,J_(H,H)=2.7, H-arom.), 6.55 (d, 1H, CH═CH), 6.22 (brt, 1H,J_(NH,4′)=6.22, NH), 4.67 (brs, 1H, H-2a or H-6a), 3.70 (brs, 1H, H-2aor H-6a), 3.38-3.32 (m, 1H, H-4′), 2.97-2.74 (m, 2H, H-2b, H-6b),1.79-0.99 (m, 11H, H-3, H-5, H-4, H-1′, H-2′, H-3′). ¹³C-NMR (75.4 MHz,CDCl₃, δ ppm) 170.5 (C═O), 165.2 (C═O), 161.2 (dd, J_(C-F)=250.2,J_(C-F)=15.0, C—F), 159.2 (dd, J_(C-F)=252.4, J_(C-F)=14.6, C—F),144.6-144.4 (m, C-arom.), 136.4 (C-arom.), 131.1 (d, J_(C-F)=3.5,C-arom.), 129.6 (CH═CH), 128.6 (C-arom.), 126.9 (C-arom.), 125.6 (d,J_(C-F)=7.6, CH═CH), 115.2 (dd, J_(C-F)=23.4, J_(C-F)=6.6, C-arom.),106.7 (dd, J_(C-F)=34.3, J_(C-F)=6.2, C-arom.), 48.2, 42.7 (C-2, C-6),39.9 (C-4′), 36.2, 36.1, 33.0, 32.0, 29.9, 24.0 (C-3′, C-2′, C-4, C-1′,C-3, C-5). HRLSIMS m/z found 450.1971, calc. for C₂₄H₂₇O₂N₃F₂Na:450.1969.

(E)-3-(2,6-difluoropyridin-3-yl)-N-4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)acrylamide (PER-202)

Same procedure as that used for the preparation of PER-201 starting with41b. Yield: (65.9 mg, 0.152 mmol, 80%, MW: 433.518) as a pale yellowoil. IR (v cm⁻¹) 3276 (NH), 1602 (C═O). ¹H NMR (300 MHz, CDCl₃, δ ppm, JHz) δ 8.00-7.91 (m, 1H, H-arom.), 7.55 (d, 1H, J_(H,H)=15.6, CH═CH),7.41 (dd, 1H, J_(H,H)=5.1, J_(H,H)=1.2, H-arom.), 7.25 (dd, 1H,J_(H,H)=4.2, J_(H,H)=1.8, H-arom.), 7.02 (dd, 1H, J_(H,H)=5.0,J_(H,H)=3.7, H-arom.), 6.85 (dd, 1H, J_(H,H)=8.1, J_(H,H)=3.0, H-arom.),6.60 (d, 1H, CH═CH), 6.22 (brt, 1H, J_(NH,4′)=5.90, NH), 4.40 (brs, 2H,H-2a, H-6a), 3.41-3.34 (m, 1H, H-4′), 2.91 (brs, 2H, H-2b, H-6b),1.77-1.73 (m, 2H, H-3a, H-5a), 1.59-1.52 (m, 3H, H-3′, H-4), 1.38-1.23(m, 4H, H-2′, H-1′), 1.21-1.11 (m, 2H, H-3b, H-5b). ¹³C-NMR (75.4 MHz,CDCl₃, δ ppm) 165.2 (C═O), 163.6 (C═O), 161.2 (dd, J_(C-F)=251.2,J_(C-F)=16.0, C—F), 159.2 (dd, J_(C-F)=251.3, J_(C-F)=14.9, C—F), 144.5(dd, J_(C-F)=8.1, J_(C-F)=4.4, C-arom.), 137.6 (C-arom.), 131.3 (d,J_(C-F)=3.9, CH═CH), 128.5 (C-arom.), 128.3 (C-arom.), 126.7 (C-arom.),125.6 (dd, J_(C-F)=8, J_(C-F)=2.2, CH═CH), 115.2 (dd, J_(C-F)=24,J_(C-F)=6.2, C-arom.), 107.0 (dd, J_(C-F)=34.6, J_(C-F)=5.8, C-arom.),46.5 (C-2, C-6), 39.9 (C-4′), 36.2, 36.1, 32.6, 29.9, 24.1 (C-3′, C-2′,C-4, C-1′, C-3, C-5). HRLSIMS m/z found 456.1538, calc. forC₂₂H₂₅O₂N₃F₂NaS: 456.1533.

(E)-3-(2,6-difluoropyridin-3-yl)-N-4-(1-(furan-2-carbonyl)piperidin-4-yl)butyl)acrylamide (PER-203

Same procedure as that used for the preparation of PER-201 starting with41c. Yield: (43.4 mg, 0.104 mmol, 55%, MW: 417.457) as a pale yellowoil. IR (v cm⁻¹) 3272 (NH), 1605 (C═O). 1H NMR (300 MHz, CDCl₃, δ ppm, JHz) δ 8.02-7.93 (m, 1H, H-arom.), 7.56 (d, 1H, J_(H,H)=15.9, CH═CH),7.46 (dd, 1H, J_(H,H)=1.8, J_(H,H)=0.9, H-arom.), 6.92 (dd, 1H,J_(H,H)=3.3, J_(H,H)=0.6, H-arom.), 6.86 (dd, 1H, J_(H,H)=10.2,J_(H,H)=2.1, H-arom.), 6.58 (d, 1H, CH═CH), 6.45 (dd, 1H, J_(H,H)=3.3,J_(H,H)=1.8, H-arom.), 6.23 (brt, 1H, J_(NH,4′)=1.6, NH), 4.48 (brs, 2H,H-2a, H-6a), 3.42-3.35 (m, 1H, H-4′), 2.91 (brs, 2H, H-2b, H-6b),1.78-1.74, 1.59-1.50, 1.39-1.12 (m, H-3, H-5, H-4, H-1′, H-2′, H-3′).¹³C-NMR (75.4 MHz, CDCl₃, δ ppm) 165.4 (C═O), 161.2 (dd, J_(C-F)=249.9,J_(C-F)=15.2, C—F), 159.3 (dd, J_(C-F)=253.0, J_(C-F)=15.2, C—F), 159.4(C═O), 144.6-144.4 (m, C-arom.), 143.7 (C-arom.), 132.5-132.1 (m,C-arom.), 131.4 (brs, CH═CH), 128.9 (d, J_(C-F)=12.4, C-arom.),125.4-125-3 (m, CH═CH), 115.9 (C-arom.), 111.3 (C-arom.), 107.0 (d,J_(C-F)=40.6), 46.6 (C-2, C-6), 40.0 (C-4′), 36.2, 36.1, 32.6, 29.9,24.1 (C-1′, C-2′, C-3′, C-4, C-3, C-5). HRLSIMS m/z found 440.1749,calc. for C₂₂H₂₅O₃N₃F₂Na: 440.1762.

(E)-3-(2,6-difluoropyridin-3-yl)-N-(4-1-(2,6-dimethoxybenzoyl)piperidin-4-yl)butyl)acrylamide (MPM-09

Same procedure as that used for the preparation of PER-201 starting with41d. Yield: (68.3 mg, 0.14 mmol, 74%, MW: 487.548) as a pale yellow oil.¹H NMR (300 MHz, CDCl₃, δ ppm, J Hz) δ 7.94 (q, 1H, J_(H,H)=7.8,H-arom.), 7.54 (d, 1H, J_(H,H)=15.8, CH═CH), 7.22 (t, 1H, J_(H,H)=8.4,H-arom.), 6.84 (dd, 1H, J_(H,H)=8.1, J_(H,H)=2.9, H-arom.), 6.56-6.51(m, 3H, CH═CH, H-arom.), 6.08 (brt, 1H, J_(NH,4′)=5.0, NH), 4.79-4.74(m, 1H, H-2a or H-6a), 3.78 (s, 3H, OCH₃), 3.76 (s, 3H, OCH₃), 3.46-3.41(m, 1H, H-2a or H-6a), 3.35 (q., 1H, J_(H,H)=6.8, H-4′), 2.90 (td, 1H,J_(H,H)=13.0, J_(H,H)=2.5, H-6b or H-2b), 2.70 (td, 1H, J_(H,H)=13.0,J_(H,H)=3.1, H-6b or H-2b), 2.17-0.85 (m, 11H, H-3, H-5, H-4, H-1′,H-2′, H-3′). ¹³C-NMR (75.4 MHz, CDCl₃, δ ppm) δ 165.3 (C═O), 165.2(C═O), 161.2 (dd, J_(C-F)=245.8, J_(C-F)=13.5, C-F), 159.3 (dd,J_(C-F)=249.1, J_(C-F)=13.5, C-F), 156.8 (C-arom.), 156.7 (C-arom.),144.5-144.3 (m, C-arom.), 131.1 (d, J_(C-F)=3.7, CH═CH), 130. (C-arom.),125.6 (d, J_(C-F)=7.5, J_(C-F)=2.3, C-arom.), 115.1 (C-arom.), 107.2 (d,J_(C-F)=6.1, C-arom.), 106.7 (d, J_(C-F)=6.0, C-arom.), 104.1 (CH═CH),56.0 (OCH₃), 55.9 (OCH₃), 47.1 (C-2 or C-6), 41.8 (C-2 or C-6), 39.9(C-4′), 36.3, 36.2, 32.9, 32.1, 29.9, 24.1 (C-3′, C-2′, C-4, C-1′, C-3,C-5).

Synthesis of 2-fluoro pyridine derivatives

This compound was obtained through Heck reaction starting fromcommercial 2-fluoro-2-iodopyridine followed by acidic deprotection.

(E)-tert-Butyl 3-(2-fluoropyridin-3-yl)acrylate (45)

Tert-butylacrylate (1.3 mL, 8.7 mmol), Pd(OAc)₂ (19.53 mg, 0.09 mmol),PPh₃ (46 mg, 0.17 mmol), EtN₃ (0.62 mL, 4.35 mmol) were added underargon atmosphere to a solution of 2-fluoro-3-iodo-pyridine (44, 200 mg,0.87 mmol) in dry DMF (2.2 mL) in a 20 mL sealed tube. The reactionmixture was stirred at 120° C. for 18 h. Water (20 mL) was then addedand the aqueous layer was extracted with EtOAc (20 mL, 3 times). Thecombined organic phases were dried, filtered and concentrated in vacuo.The residue was purified by FC (1/8 EtOAc/cyclohexane) to give 45 Yield:(185.2 mg, 0.83 mmol, 95%, MW: 223.247) as a white solid. ¹H NMR (300MHz, CDCl₃, δ ppm, J Hz) δ 8.19 (br. d, 1H, J_(H,H)=4.8, H-arom.), 7.91(m 1H, H-arom.), 7.60 (d, 1H, J_(H,H)=16.2, CH═CH), 7.22 (m 1H,H-arom.), 6.51 (d, 1H, CH═CH), 1.53 (s, 9H, —C(CH₃)₃). ¹³C-NMR (75.4MHz, CDCl₃, δ ppm) 165.5 (C═O), 161.2 (d, J_(C-F)=244.5, C—F), 148.2 (d,J_(C-F)=15.2, C-arom.), 139.2 (d, J_(C-F)=3.9, C-arom.), 134.5 (d,J_(C-F)=2.9, CH═CH), 125.0 (d, J_(C-F)=5.9, CH═CH), 121.8 (d,J_(C-F)=4.4, C-arom.), 117.9 (d, J_(C-F)=26.8, C-arom.), 81.1(—C(CH₃)₃), 28.1 (—C(CH₃)₃). HRESIMS m/z obsd. 224.1077, calc. forCl₂H₁₅O₂NF: 224.1081.

(E)-3-(2-Fluoropyridin-3-yl)acrylic acid (46)

Trifluoroacetic acid (1.3 mL) was added to a solution of 45 (160 mg,0.72 mmol) in dry CH₂Cl₂ (5.2 mL) and stirred at r.t. for 2.5 h. Thereaction mixture was then concentrated to dryness to give 46 (119.8 mg,0.72 mmol, quant.) as a white solid, that was used without purificationin the next step.

General Procedure for the Synthesis of MPM-07, MPM-08 and VAL-22-2.Strategy 1

Amide coupling reactions between carboxylic acid 46 and amines 41a, 41band 41d and, were carried out using PyBOP and DIPEA as coupling agentsgiving in good yields the following fluorinated compounds: VAL-22-2 (MW:409.505), MPM-07 (MW: 415.527) and MPM-08 (MW: 469.557)

(E)-N-(4-(1-benzoylpiperidin-4-yl)butyl)-3-(2-fluoropyridin-3-yl)acrylamide(VAL22-2))

To a solution of 41a (0.15 mmol) in DMF (0.8 mL), DIPEA (0.10 mL, 0.59mmol), 46 (37.5 mg, 0.22 mmol) and PyBOP (120 mg, 0.22 mmol) were added.The reaction mixture was stirred at 20° C. for 19 h. The solvent wasevaporated in vacuo and the resulting crude product was dissolved inEtOAc. The organic phase was washed with 1M aqueous HCl, then with asaturated aqueous solution of NaHCO₃ and water. After drying (MgSO₄),the solvent was evaporated in vacuo and the residue purified by FC (5/1CH₂Cl₂/acetone). Yield: (51.6 mg, 0.126 mmol, 84%) as a white solid. ¹HNMR (300 MHz, CDCl₃, δ ppm, J Hz) δ 8.16 (m, 1H, H-arom.), 7.79 (m, 1H,H-arom.), 7.55 (d, 1H, J_(H,H)=15.9, CH═CH), 7.36 (m, 5H, H-arom.), 7.19(m, 1H, H-arom.), 6.62 (d, 1H, CH═CH), 6.34 (brt, 1H, J_(NH,4′)=5.4,NH), 4.65 (m, 1H, H-2a or H-6a), 3.68 (m, 1H, H-2a or H-6a), 3.34 (m,1H, H-4′), 2.94 (m, 1H, H-6b or H-2b), 2.72 (m, 1H, H-6b or H-2b),1.90-1.26 (m, 11H, H-3, H-5, H-4, H-1′, H-2′, H-3′). ¹³C-NMR (75.4 MHz,CDCl₃, δ ppm) δ 170.4 (C═O), 165.3 (C═O), 162.9 (d, J_(C-F)=244.3, C-F),147.6 (d, J_(C-F)=15.4, C-arom), 140.4 (d, J_(C-F)=4.2, C-arom.), 136.4(C-arom.), 132.3 (d, J_(C-F)=4.1, CH═CH), 129.5 (C-arom.), 128.5(C-arom.), 126.8 (C-arom.), 126.1 (d, J_(C-F)=8.0, CH═CH), 121.9 (d,J_(C-F)=4.4, C-arom.), 118.3 (d, J_(C-F)=26.4, C-arom.), 46.9 (C-2 orC-6), 42.1 (C-2 or C-6), 39.8 (C-4′), 36.1, 36.0, 33.0, 31.9, 29.8, 24.0(C-3′, C-2′, C-4, C-1′, C-3, C-5). HRMS (ESI) m/z found 432.22054 for[M+Na]⁺, calc. for C₂₄H₂₈O₂N₃FNa: 432.2054.

(E)-3-(2-fluoropyridin-3-yl)-N-4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)acrylamide (MPM-07)

Same procedure as that used for the preparation of VAL22-2 starting from41b. Yield: (49.03 mg, 0.118 mmol, 79%, MW: 415.527) as a pale yellowoil. ¹H NMR (300 MHz, CDCl₃, δ ppm, J Hz) δ 8.16-8.14 (m, 1H, H-arom.),7.86-7.82 (m, 1H, H-arom.), 7.57 (d, 1H, J_(H,H)=15.8, CH═CH), 7.41 (dd,1H, J_(H,H)=5.0, J_(H,H)=1.0, H-arom.), 7.26-7.19 (m, 2H, H-arom.), 7.02(dd, 1H, J_(H,H)=5.0, J_(H,H)=3.7, H-arom.), 6.62 (d, 1H, CH═CH), 6.08(brt, 1H, J_(NH,4′)=5.5, NH), 4.40 (brs, 2H, H-2a, H-6a), 3.38 (q., 1H,J_(H,H)=6.8, H-4′), 3.01-2.79 (m, 2H, H-2b, H-6b), 1.82-1.73 (m, 2H,H-3a, H-5a), 1.61-1.52 (m, 3H, H-3′, H-4), 1.43-1.11 (m, 6H, H-2′, H-1′,H-3b, H-5b). ¹³C-NMR (75.4 MHz, CDCl₃, δ ppm) δ 165.2 (C═O), 163.5(C═O), 161.3 (dd, J_(C-F)=229, C-F), 147.5 (dd, J_(C-F)=15.3, C-arom.),140.4 (dd, J_(C-F)=4.3, C-arom.), 137.5 (C-arom.), 132.5 (d,J_(C-F)=4.5, CH═CH), 128.4 (C-arom.), 128.2 (C-arom.), 126.6 (C-arom.),126.0 (dd, J_(C-F)=8.4, CH═CH), 121.8 (dd, J_(C-F)=4.4, C-arom.), 118.2(dd, J_(C-F)=26.5, C-arom.), 45.6 (C-2, C-6), 39.8 (C-4′), 36.1, 36.0,32.5, 30.3, 30.0, 23.9 (C-3′, C-2′, C-4, C-1′, C-3, C-5). HRMS (ESI) m/zfound 438.1617, calc. for C₂₂H₂₆O₂N₃₂NaS: 438.1622.

(E)-N-(4-1-(2,6-dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(2-fluoropyridin-3-yl)acrylamide(MPM-08)

Same procedure as that used for the preparation of VAL-22-2 startingfrom 41d. Yield: (32.9 mg, 0.07 mmol, 45%, MW: 469.557) as a pale yellowoil. ¹H NMR (300 MHz, CDCl₃, δ ppm, J Hz) δ 8.16-8.14 (m, 1H, H-arom.),7.89-7.81 (m, 1H, H-arom.), 7.56 (d, 1H, J_(H,H)=15.8, CH═CH), 7.25-7.18(m, 2H, H-arom.), 6.60 (d, 1H, CH═CH), 6.54 (d, 1H, J_(H,H)=8.4,H-arom.), 6.53 (d, 1H, J_(H,H)=8.4, H-arom.), 6.02 (brt, 1H,J_(NH,4′)=5.6, NH), 4.81-4.73 (m, 1H, H-2a or H-6a), 3.78 (s, 3H, OCH₃),3.77 (s, 3H, OCH₃), 3.48-3.40 (m, 1H, H-2a or H-6a), 3.36 (q., 1H,J_(H,H)=6.9, H-4′), 2.90 (td, 1H, J_(H,H)=13.1, J_(H,H)=2.6, H-6b orH-2b), 2.73 (td, 1H, J_(H,H)=12.8, J_(H,H)=2.9, H-6b or H-2b), 1.73-1.03(m, 11H, H-3, H-5, H-4, H-1′, H-2′, H-3′). ¹³C-NMR (75.4 MHz, CDCl₃, δppm) δ 165.2 (C═O), 161.2 (d, J_(C-F)=244.3, C-F), 156.6 (C-arom.),156.5 (C-arom.), 147.5 (d, J_(C-F)=15.4, C-arom.), 140.3 (dd,J_(C-F)=4.1, C-arom.), 132.3 (d, J_(C-F)=4.1, CH═CH), 130.0 (C-arom.),126.1 (d, J_(C-F)=8, C-arom.), 121.8 (d, J_(C-F)=4.4, C-arom.), 118.2(d, J_(C-F)=26.4, C-arom.), 115.0 (C-arom.), 103.9 (CH═CH), 55.8 (OCH₃),55.7 (OCH₃), 46.9 (C-2 or C-6), 41.7 (C-2 or C-6), 39.8 (C-4′), 36.2,36.1, 32.8, 31.9, 29.8, 24.0 (C-3′, C-2′, C-4, C-1′, C-3, C-5). HRMS(ESI) m/z found 470.2442, calc. for C₂₆H₃₃O₄N₃F: 470.2450.

General Procedure for the Synthesis of MPM-10, MPM-11, MPM-12, MPM-13and MPM-14. Strategy 2

For the synthesis of the above derivatives another strategy was followedas outlined in the scheme. Reaction of amine 8 with 2-fluoroacrylic acid46 under standard amide coupling conditions afforded Boc-protectedderivative 48 in 90% yield. Acidic deprotection, quantitatively gavefree amine 49 which was coupled with hydroxymethyl carboxylic acids 39and 50 furnishing derivatives MPM-10 (MW: 443.519) and MPM-12 (MW:499.583), respectively. Dess-Martin oxidation gave, respectively, thecorresponding carbaldehydes MPM-11 (MW: 441.503), and MPM-13 (MW:497.567), in excellent yields. On its side, reaction of pyrrolecarboxylic acid 55 with 49, under the same conditions, gave derivativeMPM-14 (MW: 482.600) in 76% yield.

Hydroxymethyl benzoic acid 50 was prepared according to the reportedprocedure [Ishii, H.; Sugiura, T.; Akiyama, Y.; Ichikawa, Y.; Watanabe,T.; Murakami, Y. Chem. Pharm. Bull. 1990, 38, 2118]. Pyrrole carboxylicacid 55 was prepared by basic hydrolysis of the known ethyl ester[Garcia Gonzalez, F.; Fernandez-Bolanos, J.; Martin Jimenez de la Plata,G.; Lopez Partida, N.; Robina Ramirez, I. An. Quim. 1978, 74, 1281-1284]in 88% yield.

(E)-3-(2-Fluoropyridin-3-yl)-N-(tert-butyloxycarbonylpiperidin-4-yl)butyl)acrylamide(48)

To a solution of amine 8 (288 mg, 1.12 mmol) in dry DMF (15 mL) isdissolved, DIPEA (0.8 mL, 4.49 mmol), 2-fluroacrylic acid 46 (225 mg,1.348 mmol) and PyBOP (716 mg, 1.35 mmol) are added. The reactionmixture is left to stand at r.t. for 5 h and then concentrated todryness. The obtained crude product was dissolved in AcOEt (60 mL) andwashed successively with HCl (1M) (3×15 mL), NaHCO₃ (3×15 mL) and H₂O(3×15 mL). The organic phase is dried over Na₂SO₄, filtered andconcentrated to dryness. Purification by column chromatography on silicagel (ether:acetone, 20:1) gave 48. Yield: (405.5 mg, 1.00 mmol, 90%, MW:405.514) as a colourless oil. ¹H NMR (300 MHz, CDCl₃, δ ppm, J Hz) δ8.17-8.15 (m, 1H, H-arom.), 7.90-7.83 (m, 1H, H-arom.), 7.58 (d, 1H,J_(H,H)=15.8, CH═CH), 7.26-7.21 (m, 1H, H-arom.), 6.61 (d, 1H, CH═CH),5.88 (brt, 1H, J_(NH,4′)=5.9, NH), 4.10-4.03 (m, 2H, H-2a, H-6a), 3.39(q, 1H, J_(H,H)=6.8, H-4′), 2.65 (td, 2H, J_(H,H)=13.1, J_(H,H)=2.5,H-2b, H-6b), 1.65-0.98 (m, 11H, H-3, H-5, H-4, H-1′, H-2′, H-3′), 1.44(s, 9H, —C(CH₃)₃). HRESIMS m/z found 428.2315, calc. for C₂₂H₃₂O₃N₃FNa:428.2320.

(E)-3-(2-fluoropyridin-3-yl)-N-(4-1-(5-(hydroxymethyl-2-methylfuro-3-yl)piperidin-4-yl)butyl)acrylamide(MPM-10)

Compound 48 (265 mg, 0.654 mmol) is dissolved in a solution of 20% TFAin CH₂Cl₂ (6 mL) at 0° C. and left to stand at this temperature for 1 h,and then concentrated to dryness giving 49 in quantitavely yield. To asolution of the crude product 49 in dry DMF (7 mL), DIPEA (685 □l, 3.921mmol) is added and stirred for 5 min. Then the carboxylic acid 39 (133mg, 0.850 mmol) and PyBOP (590 mg, 1.111 mmol) are added. The reactionmixture was allowed to stand at r.t. under nitrogen for 14 h and thenconcentrated to dryness. The residue was dissolved in AcOEt (90 mL) andwashed with HCl (1M) (3×20 mL), saturated NaHCO₃ (3×20 mL) and NaClaqueous solution (3×20 mL). The organic phase is dried over Na₂SO₄,filtered and concentrated to dryness. Purification by columnchromatography of the residue on silica gel (CH₂Cl₂: MeOH, 30:1-20:1→10:1) afforded MPMN-10 (226.3 mg, 0.510 mmol, 78%, MW: 443.519)as a white solid. IR (v cm⁻¹) 3280 (NH, OH), 1597 (C═O). ¹H NMR (300MHz, CDCl₃, δ ppm, J Hz) δ 8.16-8.14 (m, 1H, H-arom.), 7.89-7.83 (m, 1H,H-arom.), 7.56 (d, 1H, J_(H,H)=15.8, CH═CH), 7.24-7.19 (m, 1H, H-arom.),6.62 (d, 1H, CH═CH), 6.20 (s, 1H, H-arom.), 6.11 (brt, 1H,J_(NH,4′)=5.6, NH), 4.66-4.41 (m, 3H, —CH₂OH, H-2a or H-6a), 3.92 (brs,1H, H-2a or H-6a), 3.24 (q, J_(H,H)=6.8, H-4′), 2.84, (brs, 2H, H-2b,H-6b), 1.83-1.09 (m, 11H, H-3, H-5, H-4, H-1′, H-2′, H-3′). ¹³C-NMR(75.4 MHz, CDCl₃, δ ppm) δ 165.4 (C═O), 165.1 (C═O), 161.4 (d,J_(C-F)=243.0, C-F), 153.0 (C-arom.), 152.1 (C-arom.), 147.7 (d,J_(C-F)=15.3, C-arom.), 140.6 (d, J_(C-F)=4.3, C-arom.), 132.6 (d,J_(C-F)=5.1, CH═CH), 126.2 (d, J_(C-F)=8.3, CH═CH), 122.0 (d,J_(C-F)=4.3, C-arom.), 118.3 (d, J_(C-F)=26.8, C-arom.), 116.8(C-arom.), 108.3 (C-arom.), 57.3 (CH₂OH), 48.0, 42.3 (C-2, C-6), 39.9(C-4′), 36.2, 36.1, 32.9, 29.9, 24.1 (C-1′, C-2′, C-3′, C-4, C-3, C-5),13.1 (CH₃). HRESIMS m/z found 466.2114, calc. for C₂₄H₃₀O₄N₃FNa:466.2113.

(E)-3-(2-fluoropyridin-3-yl)-N-(4-(1-(4-(hydroxymethyl)-2,6-dimethoxybenzoyl))piperidin-4-yl)butyl)acrylamide(MPM-12)

Same procedure as described above starting from 48 and carboxylic acid50 gave MPM-12 Yield: (189.3 mg, 0.379 mmol, 58%, MW: 499.583) as awhite solid. IR (v cm⁻¹) 3278 (NH, OH), 2935, 2854, 1603 (C═O), 1417,11243, 978, 765. ¹H NMR (300 MHz, CDCl₃, δ ppm, J Hz) δ 8.14-8.12 (m,1H, H-arom.), 7.86-7.80 (m, 1H, H-arom.), 7.54 (d, 1H, J_(H,H)=15.8,CH═CH), 7.21-7.17 (m, 1H, H-arom.), 6.62 (d, 1H, CH═CH), 6.51-6.44 (m,3H, NH, H-arom.), 4.74-4.70 (m, 1H, H-2a or H-6a), 4.61 (s, 2H, CH₂OH),3.74 (s, 3H, OCH₃), 3.72 (s, 3H, OCH₃), 3.43-3.29 (m, 3H, H-4′, H-2a orH-6a), 2.91-2.83 (m, 1H, H-2b or H-6b), 2.74-2.65 (m, 1H, H-2b or H-6b),1.75-0.98 (m, 11H, H-3, H-5, H-4, H-1′, H-2′, H-3′). ¹³C-NMR (75.4 MHz,CDCl₃, δ ppm) δ 165.5 (C═O), 165.4 (C═O), 161.3 (d, J_(C-F)=249.0, C-F),156.6 (C-arom.), 156.5 (C-arom.), 147.6 (d, J_(C-F)=15.2, C-arom.),144.5 (C-arom.), 140.3 (d, J_(C-F)=4.0, C-arom.), 132.1 (d, J_(C-F)=4.0,CH═CH), 126.3 (d, J_(C-F)=7.4, CH═CH), 122.0 (d, J_(C-F)=4.3, C-arom.),118.4 (d, J_(C-F)=26.4, C-arom.), 113.5 (C-arom.), 102.0 (C-arom.), 64.9(CH₂OH), 55.9 (OCH₃), 55.8 (OCH₃), 47.1 (C-2 or C-6), 41.9 (C-2 or C-6),39.9 (C-4′), 36.2, 32.9, 32.0, 29.8, 24.1 (C-3, C-4, C-5, C-1′, C-2′,C-3′). HRESIMS m/z found 522.2369, calc. for C₂₇H₃₄O₅N₃FNa: 522.2375.

(E)-3-(2-fluoropyridin-3-yl)-N-(4-(1-(4-formyl-2-methyl-1-propyl-1H-pyrrole-3-carbonyl)piperidin-4-yl)butyl)acrylamide(MPM-14)

Same procedure as described above starting from 48 and carboxylic acid55 gave MPM-14. Yield: (239.9 mg, 0.497 mmol, 76%, MW: 482.600) as awhite solid. IR (v cm⁻¹) 3283 (NH), 1674 (C═O), 1662, 1599 (C═O). ¹H NMR(300 MHz, CDCl₃, δ ppm, J Hz, mixture of rotamers) δ 9.67, 9.61 (2s, 1H,CHO), 8.15-8.13 (m, 1H, H-arom.), 7.90-7.84 (m, 1H, H-arom.), 7.57, 7.56(2d, 1H, J_(H,H)=15.8, CH═CH), 7.23-7.17 (m, 2H, H-arom.), 6.64, 6.63(2d, 1H, CH═CH), 6.35, 6.28 (2brt, 1H, J_(NH,4′)=5.6, NH), 4.70 (brs,1H, H-2a or H-6a), 3.76 (t, 1H, J_(1″,2″)=6.7, H-1″), 3.61 (brs, 1H,H-2a or H-6a), 3.35 (q, J_(H,H)=6.8, H-4′), 2.98-2.74, (brs, 2H, H-2b,H-6b), 2.20, 2.14 (2s, 3H, CH₃), 1.85-1.24 (m, 13H, H-3, H-5, H-4, H-1′,H-2′, H-3′, H-2″), 0.95 (t, 3H, H-3″). ¹³C-NMR (75.4 MHz, CDCl₃, δ ppm,mixture of rotamers) δ 184.4, 184.2 (CHO), 165.8 (C═O), 165.3 (C═O),161.3 (d, J_(C-F)=244.0, C-F), 147.7 (d, J_(C-F)=15.5, C-arom.),140.4-140.2 (m, C-arom.), 132.4-132.2 (m, CH═CH), 130.3 (C-arom.), 128.2(C-arom.), 128.6 (C-arom.), 126.3-126.2 (m, C-arom.), 122.7 (C-arom.),122.0 (d, J_(C-F)=4.3, CH═CH), 118.2 (C-arom.), 49.2 (0-1″), 47.3, 42.2(C-2, C-6), 39.8 (C-4′), 36.1, 35.9, 32.2, 29.9, 29.4, 24.1, 24.0, 24.1(C-1′, C-2′, C-3′, C-4, C-3, C-5, C-2″), 11.2 (C-3″), 10.4 (CH₃).HRESIMS m/z found 505.2576, calc. for C₂₇H₃₅O₃N₄FNa: 505.2585.

(E)-3-(2-fluoropyridin-3-yl)-N-(4-(1-(5-formyl-2-methylfuro-3-yl)piperidin-4-yl)butyl)acrylamide (MPM-11)

To a solution of compound MPM-10 (0.159 mmol) in CH₂Cl₂, Dess-Martinreagent (108 mg, 0.254 mmol) is added. The reaction mixture is left tostand at r.t. for 2 h. Then CH₂Cl₂ (18 mL), saturated aqueous solution(10 mL) of NaHCO₃ and Na₂S₂O₃.5H₂O (217 mg, 0.875 mmol) is added and themixture stirred for 5 min is added. Then the phases are separated. Theorganic phase is washed with saturated aqueous NaHCO₃ solution (2×15 mL)and brine (2×15 mL), dried over Na₂SO₄, filtered and concentrated todryness. Purification by column chromatography of the residue on silicagel (CH₂Cl₂: MeOH, 30:1) gave compound MPM-11. Yield: (64 mg, 0.145mmol, 91%. MW: 441.503) as a white solid. IR (v cm⁻¹) 3286 (NH), 1674(C═O), 1615 (C═O). ¹H NMR (300 MHz, CDCl₃, δ ppm, J Hz) δ 9.55 (s, 1H,CHO), 8.17-8.15 (m, 1H, H-arom.), 7.89-7.83 (m, 1H, H-arom.), 7.57 (d,1H, J_(H,H)=15.8, CH═CH), 7.24-7.20 (m, 1H, H-arom.), 7.15 (s, 1H,H-arom.), 6.61 (d, 1H, CH═CH), 5.86 (brt, 1H, J_(NH,4′)=5.6, NH), 4.54(brs, 1H, H-2a or H-6a), 3.80 (brs, 1H, H-2a or H-6a), 3.49 (q,J_(H,H)=6.8, H-4′), 2.97, (brs, 1H, H-2b or H-6b), 2.70, (brs, 1H, H-2bor H-6b), 2.48 (s, 3H, CH₃), 1.78-1.11 (m, 11H, H-3, H-5, H-4, H-1′,H-2′, H-3′). ¹³C-NMR (75.4 MHz, CDCl₃, δ ppm) δ 177.3 (CHO), 165.3(C═O), 163.1 (C═O), 161.3 (d, J_(C-F)=253.6, C-F), 159.7 (C-arom.),150.7 (C-arom.), 147.7 (d, J_(C-F)=15.3, C-arom.), 140.6 (d,J_(C-F)=4.2, C-arom.), 132.8 (d, J_(C-F)=4.6, CH═CH), 126.0 (d,J_(C-F)=8.7, CH═CH), 122.0 (d, J_(C-F)=4.5, C-arom.), 121.3 (C-arom.),119.5 (C-arom.), 118.2 (d, J_(C-F)=26.3, C-arom.), 47.7, 42.8 (C-2,C-6), 39.9 (C-4′), 36.1, 36.0, 32.0, 30.0, 24.1 (C-1′, C-2′, C-3′, C-4,C-3, C-5), 13.7 (CH₃). HRESIMS m/z found 464.1958, calc. forC₂₄H₂₈O₄N₃FNa: 464.1956.

(E)-3-(2-fluoropyridin-3-yl)-N-(4-(1-(4-formyl-2,6-dimethoxybenzoyl))piperidin-4-yl)butyl)acrylamide (MPM-13)

Same procedure as above but staring from MPM-12 (0.159 mmol) gaveMPM-13. Yield: (44.8 mg, 0.09 mmol, 58%, MW: 497.567) as a white solid.IR (v cm⁻¹) 3291 (NH), 1617, 1600 (C═O). ¹H NMR (300 MHz, CDCl₃, δ ppm,J Hz) δ 9.93 (s, 1H, CHO), 8.17-8.15 (m, 1H, H-arom.), 7.89-7.82 (m,1H,H-arom.), 7.57 (d, 1H, J_(H,H)=15.8, CH═CH), 7.24-7.19 (m, 1H,H-arom.), 7.08 (s, 1H, H-arom.), 7.07 (s, 1H, H-arom.), 6.60 (d, 1H,CH═CH), 5.89 (brt, 1H, J_(NH,4′)=5.6, NH), 4.78-4.74 (m, 1H, H-2a orH-6a), 3.88 (s, 3H, OCH₃), 3.86 (s, 3H, OCH₃), 3.41-3.34 (m, 3H, H-4′,H-2a or H-6a), 2.94 (td, 1H, J_(H,H)=12.8, J_(H,H)=2.7, H-2b or H-6b),2.75 (td, 1H, J_(H,H)=12.9, J_(H,H)=3, H-2b or H-6b), 1.81-1.06 (m, 11H,H-3, H-5, H-4, H-1′, H-2′, H-3′). ¹³C-NMR (75.4 MHz, CDCl₃, δ ppm) δ191.5 (CHO), 165.3 (C═O), 163.9 (C═O), 161.4 (d, J_(C-F)=244.0, C-F),157.3 (C-arom.), 157.2 (C-arom.), 147.8 (d, J_(C-F)=15.2, C-arom.),140.6 (d, J_(C-F)=4.2, C-arom.), 138.0 (C-arom.), 132.7 (d, J_(C-F)=4.2,CH═CH), 126.1 (d, J_(C-F)=8.2, C-arom.), 122.0 (d, J_(C-F)=4.4,C-arom.), 121.0 (C-arom.), 118.4 (d, J_(C-F)=27, C-arom.), 105.4(C-arom.), 105.3 (C-arom.), 56.3 (OCH₃), 56.2 (OCH₃), 47.0 (C-2 or C-6),41.8 (C-2 or C-6), 39.9 (C-4′), 36.3, 36.2, 32.9, 32.0, 30.0, 24.1 (C-3,C-4, C-5, C-1′, C-2′, C-3′). HRESIMS m/z found 520.2215, calc. forC₂₇H₃₂O₅N₃FNa: 520.2218.

Evaluation of the Anticancer Activity

The compounds according to the present invention were evaluated fortheir anti-tumor activities on pancreatic ductal adenocarcinoma(Panc-1). To this end, 0.5×10⁶ human malignant cells were treated withvarious concentrations (0.001-1000 nM) for 96 hours of FK866 or thecompounds according to the present invention. Subsequently cellviability was determined using either sulforhodamine assays as describedin Caffa I, et al. (Oncotarget. 2015 May 20; 6(14):11820-32) or MTTassays. Sulforhodamine B is a dye able that binds to cellular proteins.Thus, the amount of this dye, as revealed by dissolving it and bysubsequent plate reading with a spectrophotometer, is directlyproportional to the number of living cells in each well. For MTT assays,human malignant cells were plated in triplicate on 96-well plates andtreated as mentioned above. After 96 hours of incubation, 15 μL of dyesolution was added to each well and cells were incubated for anadditional 4 hours. Stop solution (100 μL/well) was added for 1 hour andthe absorbance was read at 570 nm on a spectrophotometer. To confirmwhether the cytotoxicity exerted by these compounds involves programmedcell death, drug-induced cell death was evaluated using annexin V and7AAD double staining as described by the manufacturer for assessingapoptosis or autophagic-cell death using a Beckman Coulter CytomicsGallios flow cytometer. Dead cells were identified as annexinV+ and/or7AAD+. GraphPad Prism version 7.00 (GraphPad Software, San Diego,Calif.) was used for IC₅₀ calculation. Table 1 shows IC₅₀ of exemplifiedcompounds of the present invention

TABLE 1 IC₅₀ on Panc-1 Compound IC₅₀ on Panc-1 (nM) FK866 18.4 MPM-071.5 MPM-08 6.0 MPM-09 2.0 MPM-13 15.5 MPM-14 7.54 PER-201 14.0 PER-2025.0 FEI-56 3.0 FEI-58 0.6 FEI-62 1.0 FEI-71 7.0 FEI-74 5.0 FEI-75 2.0FEI-80 9.0 FEI-81 2.3 FEI-82 0.4 FEI-83 15.0 FEI-85 2.0 FEI-154 3.9FEI-158 6.8 FEI-170 18.0 FEI-171 12.0 FEI-190 2.6 FEI-191 1.9 FEI-1922.3 FEI-193 4.8 FEI-194 5.0 FEI-195 4.6 FEI-196 5.9 FEI-198 5.0 FEI-1992.6 FEI-200 2.4 FEI-209 8.2

Pharmacokinetics Parameters

The pharmacokinetics parameters of FK866, FEI199, VAL22-2 and MPM07 weredetermined following intraperitoneal administration (IP) in female SCIDmice.

Material and Methods

-   -   SCID (Severe Combined ImmunoDeficiency) mice female total 144    -   25 mM in DMSO (dimethylsulfoxyde) of each test drug    -   Saline solution (0.9%)

Test drugs were dissolved in saline solution at 20 mg/ml. All dosingsolutions were controlled by HPLC (High-Performance LiquidChromatography) analysis. Mouse weight is estimated around 20 g.

Dose administration information is presented in Table 2.

TABLE 2 Number of Group Tested Dose level Drug animals number drug(mg/kg) route 24 1 FK866 20 IP 24 2 MPM07 20 IP 24 4 VAL22-2 20 IP 24 6FEI199 20 IP

Three mice per time point were used in each group.

Blood samples were collected on citrate at 10 min, 30 min, 1 h, 2 h, 4h, 6 h, 8 h and 24 hours after drug administration. Followingcentrifugation, resulting plasma was stored at 80° C. pendingbioanalysis. Samples were analyzed by LC-MS/MS (Liquid chromatographytandem-mass spectrometry); the lower limit of quantification achievedwas between 3 and 12 nM depending on drug. Non compartmentalpharmacokinetic analysis was performed on plasma concentration data.

Results

No obvious abnormalities were observed on dosed animals. Thepharmacokinetics parameters for each group are summarized in Table 3.

TABLE 3 FK866 MPM07 FEI-199 VAL22-2 C_(max) (ng/mL) 28147 13181 1210816894 T_(max) (h) 0.16667 0.16667 0.16667 0.16667 T_(1/2)α□□h) 0.46 0.360.31 0.46 T_(1/2)β□□h) 3.81 25.59 10.11 8.58 AUC_(0-inf) 20764 5196 52288472 (ng*h/mL) Percentage of 1.2% 2.0% 0.5% 1.4% extrapolated AUC fromT_(6 h) to infinity AUC_(0-8 h) 20654 5107 5205 8405 (ng*h/mL) CL(mL/h)9.6 38.5 38.3 23.6 AUC: Area under the curve; t½α (0 -> 6 h); t½β (6 ->24 h)

Pharmacokinetic Study—Estimation of the Parameters

-   -   Calculations carried out by using time points from 10 min to 24        h and non-compartmental approaches;    -   Terminal slope estimated with the 3 last concentrations        measurements;    -   AUC_(0-inf) calculated using the log-trapezoidal rule,        extrapolated to infinity;    -   AUC_(6-inf) calculated using the log-trapezoidal rule form time        6 h to infinity;    -   CL calculated as dose/AUC;    -   The ratio of AUC_(6-24 h)/AUC_(0-inf) quantifies the proportion        of the AUC in the terminal phase of the concentration time curve        relative to AUC_(0-inf) it corresponds to the “Percentage of        extrapolated AUC from T_(6 h) to infinity>>

The molecules according to the present invention (FEI199, VAL22-2 andMPM07) have improved and longer half-lives in the second phase (longt_(1/2ß) with low concentrations;

-   -   6 h->24 h) than FK866.

1.-21. (canceled)
 22. A compound of Formula I

wherein Ar₁ is aryl or heteroaryl, which are optionally substituted byone, two or three substituents selected from lower alkyl; lower alkoxy;formyl; hydroxyl; lower alkyl substituted by lower alkoxy or hydroxyl; Ais C_(n)H_(2n), C_(n)H_(2n−2), C_(n)H_(2n−4), wherein n=4, 5, 6, 7; B is═N—CN, oxo (═O), thio (═S); D is NH, —CH═CH—; Ar₂ is aryl or heteroarylwhich are optionally substituted by one, two or three halogensubstituents wherein, if B is oxo (═O), Ar₁ and Ar₂ are notsimultaneously phenyl and pyridine-3-yl; B and D are not simultaneously═N—CN and —CH═CH—. or a pharmaceutically acceptable salt, a racemicmixture or its corresponding enantiomers and/or optical isomers.
 23. Thecompound of formula I according to claim 22 wherein Ar₁ is phenyl;thiophen; furan; oxazole; pyrrol; which are optionally substituted byone, two or three substituents selected from lower alkyl; lower alkoxy;formyl; hydroxyl; lower alkyl substituted by one, two or three loweralkoxy or hydroxyl.
 24. The compound of formula I according to claim 22,wherein Ar₂ is pyridine; pyridazin; diazin; which are optionallysubstituted by one, two or three halogen substituents.
 25. The compoundsof formula I according to claim 22, wherein the halogen substituent isfluorine.
 26. The compound according to claim 22, wherein Ar₁ is phenyl;thiophen-2-yl; 2,4-dimethoxyphenyl; 2,6-dimethoxyphenyl;2,4,6-trimethoxyphenyl; 3-methoxyfuran-2-yl; furan-2-yl;1,2-oxazole-5-yl; 4-formyl-2,6-dimethoxyphenyl;4-(dimethoxymethyl)-2,6-dimethoxyphenyl; 5-hydroxy-2-methylfuro-2-yl;5-formyl-2-methylfuro-3-yl; 4-hydroxymethyl-2,6-dimethoxyphenyl;4-formyl-2,6-dimethoxyphenyl; 4-formyl-2-methyl-1-propyl-pyrrol-3-yl.27. The compound of formula I according to claim 22, wherein Ar₁ is2,4-dimethoxyphenyl; 2,6-dimethoxyphenyl; 2,4,6-trimethoxyphenyl. 28.The compound of formula I according to claim 22, wherein Ar₂ ispyridazi-3-yl; 2-fluoropiyridin-3-yl; 4-fluoropyridin-3-yl;5-fluoropyridin-3-yl; 2,4-difluoropyridin-3-yl;2,6-difluoropyridin-3-yl; pyridazi-4-yl; 2-fluoropyridin-4-yl;3-fluoropyridin-4-yl; 6-fluoropyridin-4-yl; 2,3-difluoropyridin-4-yl;2,5-difluoropyridin-4-yl; 3,5-difluropyridin-4-yl;2,4,5-trifluoropyridin-4-yl; pyridazine-5-yl; 1,2-diazin-4-yl.
 29. Thecompound of formula I according to claim 22, wherein Ar₂ is2-fluoropyridin-4-yl; 3-fluoropyridin-4-yl; 6-fluoropyridin-4-yl;2,3-difluoropyridin-4-yl; 2,5-difluoropyridin-4-yl;3,5-difluropyridin-4-yl; 2,4,5-trifluoropyridin-4-yl.
 30. The compoundof formula I according to claim 22, wherein B is ═N—CN.
 31. The compoundof formula I according to claim 22, wherein A is C_(n)H_(2n),C_(n)H_(2n−2) or C_(n)H_(2n) and n is
 4. 32. The compound of formula Iaccording to claim 31 wherein A is C₄H₈.
 33. The compound of formula Iaccording to claim 22, wherein A is C_(n)H_(2n), C_(n)H_(2n−2) orC_(n)H_(2n−4) and n is
 5. 34. The compound of formula I according toclaim 33, wherein A is C₅H₁₀.
 35. The compound of formula I according toclaim 22, wherein D is NH.
 36. The compound of formula I according toclaim 22, wherein A is C₄H₅ or C₅H₁₀, B is ═N—CN; D is NH; Ar₁ is2,4-dimethoxyphenyl; 2,6-dimethoxyphenyl; 2,4,6-trimethoxyphenyl; Ar₂ is2-fluoropyridin-4-yl; 3-fluoropyridin-4-yl; 6-fluoropyridin-4-yl;2,3-difluoropyridin-4-yl; 2,5-difluoropyridin-4-yl;3,5-difluropyridin-4-yl; 2,4,5-trifluoropyridin-4-yl.
 37. The compoundof formula I according to claim 22 which is(E)-3-(2-fluoropyridin-3-yl)-N-4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)acrylamide;(E)-N-(4-1-(2,6-dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(2-fluoropyridin-3-yl)acrylamide;(E)-N-(4-(1-benzoylpiperidin-4-yl)butyl)-3-(2-fluoropyridin-3-yl)acrylamide;(E)-3-(2,6-difluoropyridin-3-yl)-N-(4-1-(2,6-dimethoxybenzoyl)piperidin-4-yl)butyl)acrylamide;(E)-3-(2-fluoropyridin-3-yl)-N-(4-1-(5-(hydroxymethyl-2-methylfuro-3-yl)piperidin-4-yl)butyl)acrylamide;(E)-3-(2-fluoropyridin-3-yl)-N-(4-(1-(5-formyl-2-methylfuro-3-yl)piperidin-4-yl)butyl)acrylamide;(E)-3-(2-fluoropyridin-3-yl)-N-(4-(1-(4-(hydroxymethyl)-2,6-dimethoxybenzoyl))piperidin-4-yl)butyl)acrylamide;(E)-3-(2-fluoropyridin-3-yl)-N-(4-(1-(4-formyl-2,6-dimethoxybenzoyl))piperidin-4-yl)butyl)acrylamide;(E)-3-(2-fluoropyridin-3-yl)-N-(4-(1-(4-formyl-2-methyl-1-propyl-1H-pyrrole-3-carbonyl)piperidin-4-yl)butyl)acrylamide;(E)-N-(4-(1-benzoylpiperidin-4-yl)butyl)-3-(2,6-difluoropyridin-3-yl)acrylamide;(E)-3-(2,6-difluoropyridin-3-yl)-N-4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)acrylamide;(E)-3-(2,6-difluoropyridin-3-yl)-N-4-(1-(furan-2-carbonyl)piperidin-4-yl)butyl)acrylamide;(E)-N-(4-(1-(2,4-Dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide;(E)-N-(4-(1-(2,6-Dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide;(E)-3-(Pyridin-3-yl)-N-(4-(1-(2,4,6-trimethoxybenzoyl)piperidin-4-yl)butyl)acrylamide;(E)-N-(4-(1-(3-Methoxyfuran-2-carbonyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide;(E)-N-(4-(1-(Isoxazole-5-carbonyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide;(E)-N-(4-(1-(4-Formyl-2,6-dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)acrylamide;(E)-N-((E)-4-(1-Benzoylpiperidin-4-yl)but-2-en-1-yl)-3-(pyridin-3-yl)acrylamide;(E)-N-((E)-4-(1-(2,6-Dimethoxybenzoyl)piperidin-4-yl)but-2-en-1-yl)-3-(pyridin-3-yl)acrylamide;(E)-3-(Pyridin-3-yl)-N-((E)-4-(1-(2,4,6-trimethoxybenzoyl)piperidin-4-yl)but-2-en-1-yl)acrylamide;(E)-N-((E)-4-(1-(Furan-2-carbonyl)piperidin-4-yl)but-2-en-1-yl)-3-(pyridin-3-yl)acrylamide;(E)-3-(Pyridin-3-yl)-N-((E)-4-(1-(thiophene-2-carbonyl)piperidin-4-yl)but-2-en-1-yl)acrylamide;(E)-N-(4-(1-Benzoylpiperidin-4-yl)butyl)-3-(pyridazin-4-yl)acrylamide;(E)-N-(4-(1-(Furan-2-carbonyl)piperidin-4-yl)butyl)-3-(pyridazin-4-yl)acrylamide;(E)-3-(Pyridazin-4-yl)-N-(4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)acrylamide;(E)-N-(4-(1-(2,6-Dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridazin-4-yl)acrylamide;1-(4-(1-Benzoylpiperidin-4-yl)butyl)-3-(pyridin-3-Aurea;1-(4-(1-(Furan-2-carbonyl)piperidin-4-yl)butyl)-3-(pyridin-3-Aurea;1-(Pyridin-3-yl)-3-(4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)urea;1-(4-(1-(2,6-Dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)urea;1-(4-(1-Benzoylpiperidin-4-yl)butyl)-3-(pyridin-4-Aurea;1-(4-(1-(Furan-2-carbonyl)piperidin-4-yl)butyl)-3-(pyridin-4-Aurea;1-(Pyridin-4-yl)-3-(4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)urea;1-(4-(1-(2,6-Dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridin-4-yl)urea;(E)-1-(4-(1-Benzoylpiperidin-4-yl)butyl)-2-cyano-3-(pyridin-4-yl)guanidine;(E)-2-Cyano-1-(4-(1-(2,6-dimethoxybenzoyhpiperidin-4-yl)butyl)-3-(pyridin-4-yl)guanidine;(E)-2-Cyano-1-(4-(1-(furan-2-carbonyl)piperidin-4-yl)butyl)-3-(pyridin-4-yl)guanidine;(E)-2-Cyano-1-(pyridin-4-yl)-3-(4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)guanidine;(E)-2-cyano-1-(4-(1-(4-(dimethoxymethyl)-2,6-dimethoxybenzoyhpiperidin-4-yl)butyl)-3-(pyridazin-4-yl)guanidine;(E)-2-Cyano-1-(4-(1-(furan-2-carbonyl)piperidin-4-yl)butyl)-3-(pyridazin-4-yl)guanidine;(E)-1-(4-(1-Benzoylpiperidin-4-yl)butyl)-2-cyano-3-(6-fluoropyridin-3-yl)guanidine;(E)-2-Cyano-1-(4-(1-(2,6-dimethoxybenzoyhpiperidin-4-yl)butyl)-3-(6-fluoropyridin-3-yl)guanidine;(E)-2-cyano-1-(4-(1-(4-(dimethoxymethyl)-2,6-dimethoxybenzoyhpiperidin-4-yl)butyl)-3-(6-fluoropyridin-3-yl)guanidine;(E)-2-Cyano-1-(6-fluoropyridin-3-yl)-3-(4-(1-(furan-2-carbonyl)piperidin-4-yl)butyl)guanidine;(E)-2-Cyano-1-(6-fluoropyridin-3-yl)-3-(4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)guanidine;(E)-1-(5-(1-Benzoylpiperidin-4-yl)pentyl)-2-cyano-3-(pyridin-3-yl)guanidine;(E)-2-Cyano-1-(5-(1-(furan-2-carbonyl)piperidin-4-yl)pentyl)-3-(pyridin-3-yl)guanidine;(E)-2-Cyano-1-(pyridin-3-yl)-3-(5-(1-(thiophene-2-carbonyl)piperidin-4-yl)pentyl)guanidine;(E)-1-(5-(1-Benzoylpiperidin-4-yl)pentyl)-2-cyano-3-(pyridin-4-yl)guanidine;(E)-2-Cyano-1-(5-(1-(furan-2-carbonyl)piperidin-4-yl)pentyl)-3-(pyridin-4-yl)guanidine;(E)-2-Cyano-1-(pyridin-4-yl)-3-(5-(1-(thiophene-2-carbonyl)piperidin-4-yl)pentyl)guanidine;(E)-2-Cyano-1-(5-(1-(2,6-dimethoxybenzoyhpiperidin-4-yl)pentyl)-3-(pyridin-4-yl)guanidine;(E)-1-((E)-5-(1-Benzoylpiperidin-4-yl)pent-2-en-1-yl)-2-cyano-3-(pyridin-3-yl)guanidine;(E)-2-Cyano-1-((E)-5-(1-(furan-2-carbonyl)piperidin-4-yl)pent-2-en-1-yl)-3-(pyridin-3-yl)guanidine;(E)-2-Cyano-1-(pyridin-3-yl)-3-((E)-5-(1-(thiophene-2-carbonyl)piperidin-4-yl)pent-2-en-1-yl)guanidine;(E)-2-Cyano-1-((E)-5-(1-(2,6-dimethoxybenzoyl)piperidin-4-yl)pent-2-en-1-yl)-3-(pyridin-3-yl)guanidine;(E)-1-((E)-5-(1-Benzoylpiperidin-4-yl)pent-2-en-1-yl)-2-cyano-3-(pyridin-4-yl)guanidine;(E)-2-Cyano-1-((E)-5-(1-(furan-2-carbonyl)piperidin-4-yl)pent-2-en-1-yl)-3-(pyridin-4-yl)guanidine;(E)-2-Cyano-1-(pyridin-4-yl)-3-((E)-5-(1-(thiophene-2-carbonyl)piperidin-4-yl)pent-2-en-1-yl)guanidine;(E)-2-Cyano-1-((E)-5-(1-(2,6-dimethoxybenzoyl)piperidin-4-yl)pent-2-en-1-yl)-3-(pyridin-4-yl)guanidine;1-(4-(1-Benzoylpiperidin-4-yl)butyl)-3-(pyridin-3-yl)thiourea;1-(4-(1-(Furan-2-carbonyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)thiourea;1-(Pyridin-3-yl)-3-(4-(1-(thiophene-2-carbonyl)piperidin-4-yl)butyl)thiourea;or1-(4-(1-(2,6-Dimethoxybenzoyl)piperidin-4-yl)butyl)-3-(pyridin-3-yl)thiourea.38. A compound of formula I according to claim 22 for use astherapeutically active substance.
 39. A compound of formula I accordingto claim 22 for use in the treatment of pancreatic cancer.
 40. The useof a compound of formula I according to claim 22 for the manufacture ofa medicament for treating pancreatic cancer.
 41. A pharmaceuticalcomposition comprising a compound of formula I as claimed in claim 22and pharmaceutically acceptable excipients.
 42. A process for themanufacture of a compound of formula I according to claim 22, whichprocess comprises: a) reacting a compound of formula I

with a compound of formula 2Ar₁COOH  (2) to a compound of formula I

wherein A is C_(n)H_(2n), C_(n)H_(2n−2), C_(n)H_(2n−4) wherein n=4, 5,6, 7; B is oxo (═O); D is —CH═CH—; Ar₁ and Ar₂ are as defined in claim22; b) reacting a compound of formula 3

with a compound of formula 4

to a compound of formula I

wherein A is C_(n)H_(2n), C_(n)H_(2n−2), C_(n)H_(2n−4) wherein n=4, 5,6, 7; B is ═N—CN; D is NH; Ar₁ and Ar₂ are as defined in claim 22; c)reacting a compound of formula 3

with a compound of formula 5

to a compound of formula I

wherein A is C_(n)H_(2n), C_(n)H_(2n−2), C_(n)H_(2n−4) wherein n=4, 5,6, 7; B is oxo (═O); D is NH; Ar₁ and Ar₂ are as defined in claim 22; d)reacting a compound of formula 3

with a compound of formula 6Ar₂NCS  6 to a compound of formula I

wherein A is C_(n)H_(2n), C_(n)H_(2n−2), C_(n)H_(2n−4) wherein n=4, 5,6, 7; B is thio (═S); D is NH; Ar₁ and Ar₂ are as defined in claim 22;e) reacting a compound of formula 7

with a compound of formula 2Ar₁COOH  (2) to a compound of formula I

wherein A is C_(n)H_(2n), C_(n)H_(2n−2), C_(n)H_(2n−4) wherein n=4, 5,6, 7; B is thio (═S); D is —CH═CH—; and Ar₁ and Ar₂ are as defined inclaim 22.